In today’s market, it seems like all 3D scanners have similar specifications, as if manufacturers look at their competitors’ data and use the same numbers. Datasheets, marketing videos, and even product appearances all look comparable, making it difficult to distinguish quality based on technical data alone.So, when faced with multiple options, how can we identify a high-quality 3D scanner?In this blog post, Creaform presents three practical tests that require no calibrated artifact to determine whether the <a href="https://www.creaform3d.com/blog/the-difference-between-stated-accuracy-and-accredited-accuracy/">performance claimed on technical specification sheets is achievable in real-life scenarios</a> or just numbers without tangible value on paper. These tests are intended to help you identify which manufacturers have rigorously developed and tested their 3D scanners.<h2 id="isPasted">Form Defect Measurement (Cylindricity)</h2>In <a href="https://www.creaform3d.com/blog/what-is-gdt-basics-and-definitions/">GD&amp;T</a>, a form defect is the deviation of a machined part from its ideal shape, such as a plane or a cylinder. A form defect measurement is a good indication of the 3D scanner’s quality because it shows the sensor’s ability to measure the true value of the form defect. <a href="https://www.creaform3d.com/en/portable-3d-scanners">High-quality 3D scanners</a> will provide measurements very close to the nominal value, while poor-quality 3D scanners may show significant deviations.<h2>Test #1: Cylindricity Test</h2>A simple cylindricity test can provide valuable insights into the 3D scanner’s raw data quality.When assessing the quality of a 3D scanner, the primary consideration is the raw data, which undergoes an extensive point filtering process. No doubt, if the raw data is noisy and of low quality, it will lead to questionable 3D models.See how to perform a cylindricity test<h3>The Result: A Cylinder or a Mushroom</h3>If, at high resolution, you are unable to obtain a good cylindricity value and clearly see the edge of the cylinder at right angles, it suggests that the sensor is capturing poor-quality raw data. This raises concerns about the entire data capture and analysis process.When a cylinder looks like a mushroom, it indicates that the 3D scanner’s raw data is noisy. As a result, the software uses reconstruction algorithms to smooth the cylinder’s body and edges (and make the data look better), creating a mushroom shape. However, these algorithms can cause various unintended effects.&nbsp;Poor-quality raw data with lots of noise means a thick point cloud. Therefore, how do we know where the real surface is in this point cloud? How can we ensure the mesh is created using accurate raw data and real surface points? Are there any hidden smoothed surfaces at high resolution that might affect the accuracy of the mesh?<img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1730455359522-3-simple-tests-2-Low-Quality-3D-Scanners-Results-1536x864.webp" style="width: 100%px;" class="fr-fic fr-dib">Mushroom effect visible with a low-quality 3D scanner<h2 id="isPasted">Creaform, Inventor of the Handheld 3D Scanner</h2>As the pioneer of handheld 3D scanners, Creaform possesses unique expertise that ensures the quality of acquired data with minimal noise. Consequently, surface reconstruction algorithms perform more effectively because they do not need to smooth low-quality surface points, thus guaranteeing <a href="https://www.creaform3d.com/blog/results-revealed-and-facts-exposed-benchmarking-two-3d-scanning-metrology-solutions-to-save-inspection-time/">consistently high quality</a>.<img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1730455385221-3-simple-tests-1-MetraSCAN-Black_Elite-results-1536x864.webp" style="width: 100%px;" class="fr-fic fr-dib">Evidence supporting the claim: Cylindricity measured with Creaform’s MetraSCAN BlackTM|Elite<h2 id="isPasted">Test #2: Volumetric Accuracy Test</h2>This test aims to show the consistency of the 3D scanner’s measurements. A high-quality 3D scanner must be repeatable, i.e., produce repeatable measurements with minimal variation. In contrast, a low-quality 3D scanner may yield inconsistent results when measuring the same part multiple times or when measured by several operators.Consequently, when measurements are taken multiple times on the same part, the results must be grouped and similar whether one or several operators take them.Repeatability test: One operator performs five consecutive measurementsReproducibility test: Five operators each perform the same measurementBoth tests should present grouped results.A calibrated reference tool or artifact is not required to assess volumetric accuracy. You can measure any part within a certain period (e.g., same day, same hour). The results are even more evident on large parts.See how to perform a volumetric accuracy test<h3>The Result: Same Part, Identical Dimensions or Not</h3>If the results are not grouped, it is a good indicator that the <a href="https://www.creaform3d.com/blog/do-you-have-confidence-in-your-3d-measurements-are-you-certain-they-are-accurate-repeatable-and-reliable/">volumetric accuracy</a> claimed on the datasheet is probably wrong.<img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1730455406648-Maximum-Deviation-Graph-1536x621.webp" style="width: 100%px;" class="fr-fic fr-dib">Ungrouped results obtained with a 3D scanner of similar price (gray columns) compared with the volumetric accuracy measured with the Creaform HandySCAN Black+TM|Elite (Blue columns)If you measure the distance between two planes that are 2 meters apart, and this distance varies by more than 15µm/m, meaning 30µm over two consecutive measurements, it is difficult to claim that the 3D scanner has a volumetric precision of 15µm/m.In other words, if you measure a car twice in a row, and the first time it measures a certain dimension, and the second time it measures 2mm less, how can the sensor have a volumetric accuracy below 1mm/m? And, when two measurements differ, which one is the correct one?<h2>Creaform, 20+ Years of Innovation in 3D Scanning</h2>Creaform has encountered similar issues during its initial years of research and development but has developed the knowledge and expertise to overcome and solve them. Given Creaform’s 10-year lead in innovation and product development over other 3D scanner manufacturers in the market, we can see what problems some manufacturers have been unable to resolve.<h2>Test #3: Thermal Stability Test</h2>Another indicator of a 3D scanner’s quality grade is its performance under varying environmental conditions, such as temperature. High-quality 3D scanners are designed to remain stable under different conditions, while poor-quality scanners may be more susceptible to environmental changes.Another way to distinguish high from low quality is the frequency to which the 3D scanner requires recalibration to maintain accuracy. High-quality 3D scanners generally remain calibrated for longer periods. In contrast, poor-quality 3D scanners might drift quickly and require frequent recalibration.To perform this test, simply connect your 3D scanner and measure a part, any part. Then, repeat the measurement after 20 minutes, 1 hour, and 2 hours. Then, place the results on top of each other. Are the results consistent?See how to perform a thermal stability test<h3>The Result: Constant Recalibration Required or Not</h3>With high-quality 3D scanners, various mechanisms (mainly software) manage thermal expansion within the sensor, ensuring stable and reliable measurements over a long period of time. However, these mechanisms are absent for low-quality 3D scanners, so results tend to drift.The solution to address repeatability and thermal drift issues is to recalibrate the 3D scanner. However, it can quickly become inconvenient, even painful, for users to recalibrate their sensor each time they use it throughout the day.<img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1730455428978-Thermal-Drift-Graph-1536x849.webp" style="width: 100%px;" class="fr-fic fr-dib">Drifted results obtained with a 3D scanner of similar price (gray line) compared with the thermal stability measured with the Creaform HandySCAN Black+TM|Elite over 15 minutes<h2 id="isPasted">Creaform: High-Quality Born from Rigor and Learning</h2>Since 2005, Creaform has gained extensive knowledge and expertise in software development and mechanical design. This expertise includes lens design, finite element analysis of component heating, heatsink location, and more.All this expertise in mechanical engineering has been developed for both the optomechanical structure (developing the lenses to the CMOS sensor) and the physical structure (precisely placing the handgrip on the external structure of the sensor to avoid applying pressure and moving the cameras). This insight also includes the user and factory calibration processes.Thanks to this continuous learning and improvement, Creaform has consistently been able to subtract micrometers—not only on the specification sheet but in real life. This is what we refer to as&nbsp;accredited accuracy (link to previous blog). Our focus goes beyond numbers written on data sheets. We strive to demonstrate and maintain stability and repeatability in real-world applications, always aiming to showcase the high quality of Creaform 3D scanners.

In this blog post, Creaform presents three practical tests that require no calibrated artifact to determine whether the performance claimed on technical specification sheets is achievable in real-life scenarios or just numbers without tangible value on paper.

3 Simple Tests to Recognize High-Quality 3D Scanners with no Calibrated Artifacts Required

Author: &nbsp;Mr. Naveen Balla, <a href="mailto:info@hamamatsu.de" rel=" noopener" target="_blank" data-hook="WebLink">info@hamamatsu.de</a>The production of printed electronics represents a transformative approach to manufacturing electronic devices. Switching from complex technologies like etching or lithography to a printing process significantly simplifies production, offering a cost-effective, versatile, and straightforward pathway to fabricating electronic components on various substrates. As a result, printed electronics are used in a wide range of devices, including flexible displays, thin-film transistors, sensors, and photovoltaic cells.While already common in various industries, production equipment for printed electronics still has room for improvement to optimize manufacturing efficiency. One important aspect of this optimization, especially when using metal nanoparticle inks, is the sintering process. The sintering step includes fusing the metal nanoparticles in ink ensuring the required low resistivity of the finished circuits. For this task, heating ovens, NIR emitters, and broadband flash lamps are established technologies, but they suffer from drawbacks that limit the speed or efficiency of production.In this article, we present five aspects of printing equipment that can be improved by switching to laser sintering.<img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1723630490891-Screenshot+2024-08-14+103530.png" style="width: 100%px;" class="fr-fic fr-dib"><figure data-id="a40d2fcd-0356-4948-96f1-48a3495831b9" id="isPasted"><figcaption>Table 1: Comparison of different sintering methods</figcaption></figure><hr><h2>We are exhibiting!</h2><a rel="noopener noreferrer" href="https://www.techblick.com/electronicsreshaped" target="_blank">Visit our booth at the flagship TechBlick event in Berlin on 23-24 October 2024.</a> Let's RESHAPE the Future of Electronics together, making it Additive, Sustainable, Flexible, Hybrid, &nbsp;Wearable, Structural, and 3D.<img src="https://images.wevolver.com/eyJidWNrZXQiOiJ3ZXZvbHZlci1wcm9qZWN0LWltYWdlcyIsImtleSI6ImZyb2FsYS8xNzIyNjA5NzQ0NDUzLUhhbWFtYXRzdS1Cb290aC1CZXJsaW4yMDI0LmpwZyIsImVkaXRzIjp7InJlc2l6ZSI6eyJ3aWR0aCI6OTUwLCJmaXQiOiJjb3ZlciJ9fX0=" style="width: 100%px;" class="fr-fic fr-dib"><h3><img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1723630520058-Screenshot+2024-08-14+103712.png" style="width: 100%px;" class="fr-fic fr-dib"></h3><h3 id="isPasted">1. Reducing the footprint of the printing machine</h3>Furnaces for sintering printed electronics can be large, particularly for serial production. As the sintering process in the oven takes a few to tens of minutes, it typically does not match the production rate of the preceding printing process. To maintain high production rates, more furnaces or long conveyors are required, resulting in a large machine footprint.Laser sintering offers a solution for developing more compact machines. Since the sintering process using NIR laser takes only milliseconds, it can be performed on the conveyor directly after printing, making roll-to-roll processes possible. For machines with limited space, laser sintering provides even more flexibility. As the laser light is coupled into a fibre, it can be flexibly guided over longer distances, allowing separation of the light output from the laser source and its electronics. This minimizes the space required at the light output, enabling smaller sintering machines for confined production areas.<img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1723630540435-Screenshot+2024-08-14+104251.png" style="width: 430px;" class="fr-fic fr-dib">Laser sintering is the process where laser is used to heat metal nano/ micro particles to the point that they fuse without completely melting.<h3>2. Increase production speed.</h3>Switching from a furnace-based sintering process to laser sintering reduces space requirements and helps increase production speed. While the sintering process in a hot air oven takes a few to tens of minutes, NIR laser light sinters the metal ink within milliseconds. This allows high printing speeds and ensures that the sintering step is no longer the production bottleneck. Laser sintering significantly enhances production speed due to the easily scalable laser power, which maintains precise focus with line optics. Depending on the ink and substrate, laser technology allows for speeds of several hundred millimeters per second in roll-to-roll production, substantially increasing output rates.<img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1723630595820-Image-1.jpg" style="width: 600px;" class="fr-fic fr-dib">Example of Hamamatsu's SPOLD® laser sintering of conductive inks.<h3>3. Optimizing energy efficiency</h3>Energy efficiency is now one of the most important aspects of any production process. Minimizing energy consumption is essential to meet sustainability goals and to reduce production costs, given rising energy prices.The production of printed electronics involves many energy-intensive processes. One example is the sintering step, which requires intense heating to achieve the desired conductivity of the ink, often exceeding 100°C, depending on the nanoparticles. It is an energy-intensive process with significant production costs. Large ovens, commonly used for this process, must heat both the part and the air inside the oven to the target temperature, consuming substantial amounts of power, often 60kW or more. Alternative sintering technologies, such as photonic sintering, also demand considerable power. For instance, flash lamps used during a roll-to-roll process require 5kW of electrical power or more.Laser sintering offers a more energy-efficient solution, due to its high conversion efficiency from electrical power to light power and excellent conversion rate. Typical laser sources for laser sintering, such as the <a rel="noopener noreferrer" href="https://www.hamamatsu.com/eu/en/product/lasers/applied-products-of-semiconductor-lasers.html" target="_blank">Hamamatsu SPOLD® [1,2]</a> consume around 1kW, while still enabling fast roll-to-roll production. This improved efficiency can significantly reduce production costs over the lifetime of a production machine. <img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1723630641370-Screenshot+2024-08-14+104810.png" style="width: 100%px;" class="fr-fic fr-dib"><figure data-id="4853d99d-1f37-4121-bfd8-0f8654721f23" id="isPasted"><figcaption>Table 2: Comparison of different sintering temperatures for different nanoparticle inks on glass substrates.[3]</figcaption></figure><hr><h3>We are speaking!</h3><a rel="noopener noreferrer" href="https://www.techblick.com/electronicsreshaped" target="_blank">Join us at the flagship TechBlick event in Berlin on 23-24 October 2024.</a> Let's RESHAPE the Future of Electronics together, making it Additive, Sustainable, Flexible, Hybrid, &nbsp;Wearable, Structural, and 3D.&nbsp;<img src="https://images.wevolver.com/eyJidWNrZXQiOiJ3ZXZvbHZlci1wcm9qZWN0LWltYWdlcyIsImtleSI6ImZyb2FsYS8xNzIyNjA5ODE3MTE2LUhhbWFtYXRzdSBQaG90b25pY3MtU3BlYWtlciBDYXJkcyAoQkVSTElOLU9jdC0yMDI0KS5qcGciLCJlZGl0cyI6eyJyZXNpemUiOnsid2lkdGgiOjk1MCwiZml0IjoiY292ZXIifX19" style="width: 100%px;" class="fr-fic fr-dib"><h3 id="isPasted">4. Enabling the use of thermo-sensitive materials</h3>One of the significant advantages of printed electronics is the versatility of substrates, enabling electronics to be integrated into various materials like packaging or clothing. However, high sintering temperatures, typically around 200°C for materials like silver nanoparticles, limit the substrates that can be used. For instance, plastics such as polyethylene (PE) begin to soften at temperatures above 70°C, making it impractical to sinter them in furnaces operating at 200°C or higher.Laser sintering provides the solution. As ink and substrates have different absorption properties, it is possible to select a wavelength where the light is only absorbed in the ink while the substrate remains transparent. As a result, only the ink is heated to the required sintering temperature while the substrate remains unaffected. This allows thermo-sensitive materials, such as plastic foils, to be used, which is advantageous for the packaging industry.However, heat dissipation from the ink into the substrate can still indirectly heat and damage it. Therefore, it is essential to tailor the heating illumination to the properties of the materials. Laser sintering has many advantages over photonic sintering using flash lamps as the optimum wavelengths can be chosen depending on the application. The Hamamatsu SPOLD®, for example, is available at 940nm (optional 808nm), minimizing substrate heating compared to the broader spectrum of tungsten lamps.The laser also offers more precise control of power compared to flash lamps, allowing fine adjustment to stay below the melting temperature of the substrate. This precise control further reduces potential substrate damage, crucial when printing on highly thermo-sensitive materials like PET.<img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1723630676979-Screenshot+2024-08-14+104943.png" style="width: 100%px;" class="fr-fic fr-dib">Hamamatsu's LD irradiation light source (SPOLD®)<h3>5. Reducing ink costs</h3>In addition to the flexibility of substrates, one of the significant advantages of printed electronics is the low production cost. Laser sintering can further reduce costs by switching to less expensive inks. Due to the silver nanoparticles dissolved in the ink, it becomes quite an expensive consumable. Indeed, cheaper alternatives, like copper or aluminium offer similar conductivity values but require different sintering parameters to find the optimum conductivity, strength, and adhesion results.For this optimization, the flexibility of laser sintering is beneficial. Hamamatsu collaborates with several ink manufacturers worldwide to support manufacturers when switching ink materials. Together, they test several micro and nano ink formulations to find their optimum sintering parameters, giving customers a head start when switching to cheaper inks. <h3>Laser Sintering increases productivity</h3>Switching to laser sintering can significantly impact the productivity of printed electronics production. The laser adds the necessary flexibility to your process and enables the optimization of important parameters like resistivity, density, and adhesion by choosing the optimum ink type, laser power, or conveyor belt speed. Application tests are essential to maximize this increase in productivity. Hamamatsu Photonics supports customers with dedicated application engineers who conduct sintering tests to identify the optimum set of parameters. This simplifies the transition to new laser sintering technology and ensures customers get the most out of their printed electronics production.For more information on our SPOLD® device or on this topic, please contact: <a rel="noopener noreferrer" href="mailto:info@hamamatsu.de" target="_blank">info@hamamatsu.de</a><hr><h3 id="isPasted">References</h3>[1] Hamamatsu Photonics, LD irradiation light sources (SPOLD®): <a rel="noopener noreferrer" href="http://www.hamamatsu.com/eu/en/product/lasers/applied-products-of-semiconductor-lasers" target="_blank">www.hamamatsu.com/eu/en/product/lasers/applied-products-of-semiconductor-lasers</a><a rel="noopener noreferrer" href="https://www.hamamatsu.com/eu/en/product/lasers/applied-products-of-semiconductor-lasers.html" target="_blank">[2] Hamamatsu Photonics, "Weld, Solder, Cure or Sinter with SPOLD®":</a>&nbsp; <a rel="noopener noreferrer" href="http://www.youtube.com/watch?v=I0sLZBR9u_I" target="_blank">www.youtube.com/watch?v=I0sLZBR9u_I</a>[3] A Review on Printed Electronics, 2021: Fabrication Methods, Inks, Substrates, Applications and Environmental Impacts: <a rel="noopener noreferrer" href="http://doi.org/10.3390/jmmp5030089" target="_blank">doi.org/10.3390/jmmp5030089</a><hr><h2 data-pm-slice="1 1 []" id="isPasted"><a href="https://www.techblick.com/electronicsreshaped" rel="noreferrer noopener" target="_blank" data-hook="WebLink">Join us at the flagship TechBlick event in Berlin on 23-24 October 2024.</a></h2><h3 data-pm-slice="1 1 []">Let's RESHAPE the Future of Electronics together, making it Additive, Sustainable, Flexible, Hybrid, &nbsp;Wearable, Structural, and 3D.</h3><img src="https://images.wevolver.com/eyJidWNrZXQiOiJ3ZXZvbHZlci1wcm9qZWN0LWltYWdlcyIsImtleSI6ImZyb2FsYS8xNzIyNjA5OTM4Nzk3LUJlcmxpbiAyMDI0LUxPR08tU3BlYWtlcnMtRXhoaWJpdG9ycy5qcGciLCJlZGl0cyI6eyJyZXNpemUiOnsid2lkdGgiOjk1MCwiZml0IjoiY292ZXIifX19" style="width: 100%px;" class="fr-fic fr-dib"><h2>Save the Date! The Future of Electronics RESHAPED 2025</h2><img src="https://images.wevolver.com/eyJidWNrZXQiOiJ3ZXZvbHZlci1wcm9qZWN0LWltYWdlcyIsImtleSI6ImZyb2FsYS8xNzIyNjEwMDA3MTY0LVNlZS15b3UtbmV4dC15ZWFyICgxOTIweDEwODApLmpwZyIsImVkaXRzIjp7InJlc2l6ZSI6eyJ3aWR0aCI6OTUwLCJmaXQiOiJjb3ZlciJ9fX0=" style="width: 100%px;" class="fr-fic fr-dib">The production of printed electronics represents a transformative approach to manufacturing electronic devices. Switching from complex technologies like etching or lithography to a printing process significantly simplifies production, offering a cost-effective, versatile, and straightforward pathway to fabricating electronic components on various substrates. As a result, printed electronics are used in a wide range of devices, including flexible displays, thin-film transistors, sensors, and photovoltaic cells.While already common in various industries, production equipment for printed electronics still has room for improvement to optimize manufacturing efficiency. One important aspect of this optimization, especially when using metal nanoparticle inks, is the sintering process. The sintering step includes fusing the metal nanoparticles in ink ensuring the required low resistivity of the finished circuits. For this task, heating ovens, NIR emitters, and broadband flash lamps are established technologies, but they suffer from drawbacks that limit the speed or efficiency of production.In this article, we present five aspects of printing equipment that can be improved by switching to laser sintering.

The production of printed electronics represents a transformative approach to manufacturing electronic devices. But it is difficult and time and space consuming to sinter/cure printed electronics using conventional methods. Learn how laser sintering helps, saving time, energy, equipment space, etc?

Optimize printed electronics manufacturing with laser sintering

Researchers from ITMO University have <a href="https://pubs.acs.org/doi/10.1021/acs.nanolett.4c01475" target="_blank" id="isPasted">developed</a> a system that can bind and control particles of light and matter. While the bound particles can become a more efficient and eco-friendly substitute for electricity, the device itself may serve as a foundation for advanced computers, communications means, and internet networks.The transition from electronic to photonic devices is one of the most promising and hotly debated technological scenarios in science today. Photonic devices are analogs of everyday devices, such as computers, that use the energy of light particles rather than electricity. Although photonic technology-based devices are more energy-efficient and eco-friendly, as well as faster at transferring and processing information, they are, on the other hand, fairly large when compared to their electronic counterparts. Furthermore, the complete shift would be an expensive and time-consuming process.Therefore, a team of scientists from ITMO University have found the middle ground between photonic and electronic devices. The developed system is controlled by both light and electricity and is powered by interconnected particles of light and excitons, which are bound electron-hole states that form upon the excitation of electrons. Such quasiparticles are known as exciton-polaritons. They are also called “liquid light” because they, on one hand, act as light particles and on the other – possess properties of matter, and can be controlled without much effort. Additionally, the connections between exciton-polaritons are greater than those between photons, making it easier to work with them.&nbsp;<img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1721610184120-1381703.jpg" style="width: 100%px;" class="fr-fic fr-dib">The device. Photo courtesy of the developersThe team developed a thin plate made of several layers. A photonic crystal – a tantalum oxide lattice covered with a three-atom-thick film of molybdenum diselenide – is placed on a silicon oxide substrate. The plate is activated by a laser beam. When light lands on the device, the lattice is pumped with photons, while electrons in molybdenum diselenide start to transition into an excited state and generate excitons. Then, the photons combine with the excitons and thus produce the said exciton-polaritons.&nbsp;<blockquote>“Our technology makes it possible to not only turn the device on and off, but also regulate two states of exciton-polaritons that correspond to various light wavelengths. The states can be activated simultaneously or independently with varying power. This can be achieved either via a laser beam or by altering the plate’s voltage. We’re also investigating how the states are triggered by voltage and laser power. Knowing that, we can understand when exciton-polaritons transition from one state to another. This is a step towards high-precision particle control,” explains Vasily Kravtsov, a senior researcher at ITMO's Faculty of Physics and an employee at the Frontier Laboratory "Functional Materials for Polaritonic Quantum Logic."</blockquote>The invention may be integrated into complex devices to decrease power consumption and enhance their operational efficiency. Among such devices are optical computers that are based on neural networks and can maximize the potential of AI. The technology can also serve as an interface for internet infrastructures. Additionally, it may become a part of optical regulators and modulators used to transmit and process data, as well as network switches, which transfer energy and direct it to a system’s components.&nbsp;The study was carried out within the Priority 2030 national program at the Frontier Laboratory “Functional Materials for Polaritonic Quantum Logic”

The device. Photo courtesy of the developers

Researchers from ITMO University have developed a system that can bind and control particles of light and matter.

Scientists Develop a Device to Control Light and Matter Quasiparticles

<h2 id="isPasted">A training center at the cutting edge of progress</h2>The aeronautics industry is without question a dynamic sector of activity where progress takes place at breakneck pace and where the players in the field have to deal with remarkable technological advances that follow each other at increasingly shorter intervals. This industry would therefore very likely find itself lagging behind considerably without the support of continually updated training programs and lecturers who keep a close eye on market developments.And this is exactly what happens at the&nbsp;<a href="https://www.polyaero05.fr/le-centre/" target="_blank">POLYAÉRO® Hautes-Alpes</a> Center of Excellence, which is managed by FORMASUP MÉDITERRANÉE and where a research laboratory is used to ensure that new technologies and the latest aeronautical practices are included in the learners’ educational and technological pathway.Harnessing virtual reality (VR) and augmented reality (AR) tools, this immersive laboratory makes it possible for students to examine and handle aeronautical parts and even entire aircraft interactively. However, making digital twins and 3D models available in VR requires reliable scan data to be collected using devices of proven metrological quality, and then post-processed in an intuitive and user-friendly software ecosystem.In the wake of these numerous improvements, POLYAÉRO® Center of Excellence thus found itself in need of reliable means for digitizing parts and models that could be moving or static, large or small.<h2>Versatile equipment, lasting results</h2>One of the aircraft that was scanned for 3D imaging at POLYAÉRO® is a PC-6 Porter, a paratrooper transport aircraft. With a length of eleven meters and a wingspan of sixteen meters, this aircraft from Swiss aircraft manufacturer PILATUS Aircraft presented specific challenges that this scanner was able to handle thanks to its shape, size and mobility.The industrial project carried out by the students required studying the conversion of a thermal-powered aircraft into an electric aircraft. This involved creating a digital twin of the entire PC-6 Porter.It is important to note that before POLYAÉRO® acquired Creaform’s solutions, scanning was done using a measuring arm equipped with a scanner head, which made data acquisition more complex. In fact, unlike the various CREAFORM scanners, this solution was not suitable to meet their need for flexibility.ScanningThe scanning device that was chosen had to meet the following indispensable conditions:<ul><li>Ergonomic</li><li>Compatible with the digitization of moving and very large objects and parts.</li></ul>This led POLYAÉRO® to choose&nbsp;<a href="https://www.creaform3d.com/en" target="_blank">Creaform</a> scanners and photogrammetry systems:<ul><li>The&nbsp;<a href="https://www.creaform3d.com/en/optical-3d-scanner-metrascan" target="_blank">MetraSCAN 3D</a> for scanning the exterior of the aircraft</li><li>The&nbsp;<a href="https://www.creaform3d.com/en/handheld-portable-3d-scanner-goscan-3d" target="_blank">Go!SCAN 3D</a> and the&nbsp;<a href="https://www.creaform3d.com/en/handyscan-3d-silver-series-professional-3d" target="_blank">HandySCAN 3D|SILVER</a> for the interior</li><li>The&nbsp;<a href="https://www.creaform3d.com/en/metrology-solutions/optical-measuring-systems-maxshot-3d" target="_blank">MaxSHOT 3D&nbsp;</a>for creating a common marker inside and outside the aircraft</li></ul>The scan data was collected within a very short time and then served as the basis for the rest of the project, including retrofitting the aircraft with an electric motor and batteries, all in 3DEXPERIENCE (formerly CATIA V5, from the software publisher Dassault Systèmes).Animated in VR in an appropriate setting, the aircraft’s digital twin was given various modifications which, once validated, were adapted in augmented reality.<h3>A simple but powerful software platform</h3>Reverse engineeringAfter a 3D scan of the aircraft was rendered in real time using Creaform’s various measurement solutions, reverse engineering could start. The geometries thus captured were processed in Creaform’s software module <a href="https://www.creaform3d.com/en/metrology-solutions/3d-applications-software-platforms/vxmodel-scan-cad-software-module" target="_blank">VXmodel</a> by a group of students in training. The reverse engineered components were then reconstructed using 3DEXPERIENCE software.<img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1714726741746-Polyaero_image_3d.webp" style="width: 100%px;" class="fr-fic fr-dib">With its intuitive interface, ease of use and fast processing times, the&nbsp;<a href="https://www.creaform3d.com/en/vxelements-viewer" target="_blank">VXelements</a> platform has become an essential tool for setting up a library of 3D models that are derived from scans or formed through reverse engineering. This constantly evolving database fuels the technological projects as well as the digital libraries of the immersive VR and AR laboratory.The POLYAÉRO® Hautes Alpes Center of Excellence is at the forefront of educational innovation, offering its students all the hardware and software resources they need to build solid skills for the professions of the future in the aeronautical industry.<a href="https://www.creaform3d.com/blog/pun5th75ef_wp/wp-content/uploads/Polyaero_equipe31.jpg" target="_blank"> </a><img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1714726755539-Polyaero_equipe31.webp" style="width: 100%px;" class="fr-fic fr-dib">“The ease with which we can use Creaform’s 3D scanners makes it easier for us to train our students in reverse engineering. Direct meshing is a distinct advantage in post-processing, as is the ability to scan an aircraft in the same repository using several scanners simultaneously,” sums up Killian Marandel, operational manager at POLYAÉRO®.The future of the industry and training&nbsp;At the POLYAERO® Hautes Alpes Center of Excellence, students choose their own technological projects and use 3D scanners to study discrepancies between design and production, deformations and reverse engineered models.The team of design engineers and lecturers need a large number of 3D models of parts in order to enrich the library and integrate them into virtual or augmented reality teaching materials.To do this, the center scans parts of all sizes and aircrafts to complete existing models or create new ones. It is thanks to this updating of databases and knowledge that POLYAÉRO® and the industry in general is evolving rapidly and almost organically. Creaform is thrilled to be part of this adventure.<img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1714726768301-Polyaero_equipe2-1536x1152.webp" style="width: 100%px;" class="fr-fic fr-dib">

The aeronautics industry is without question a dynamic sector of activity where progress takes place at breakneck pace and where the players in the field have to deal with remarkable technological advances that follow each other at increasingly shorter intervals.

Electrifying an Aircraft Using 3D Scanning and Augmented Reality

Selective laser sintering (SLS) 3D printing is considered one of the most reliable and productive forms of additive manufacturing.[1] Recently, advances in hardware are improving SLS printing even further, enabling even better surface finish quality and achievable level of fine details.&nbsp;At <a href="https://sintratec.com/" target="_blank" rel="noopener noreferrer">Sintratec</a>, a Swiss maker of professional SLS systems, these advances are in the form of high-precision lasers with spot sizes significantly smaller than other entry-level SLS systems. This has enabled Sintratec to achieve unparalleled print resolutions and feature sizes on its SLS platforms. In this article, we look at what laser spot size is, how it influences print resolution, and how Sintratec’s technologies are unlocking new opportunities for SLS users.<h2 dir="ltr">The Science of Laser Spot Size</h2>Selective Laser Sintering is an additive manufacturing technique that fabricates parts by sintering powdered material using a laser. The process begins by depositing a thin layer of polymer powder onto a build platform. A high-powered laser then selectively scans the surface, melting and fusing the powder according to the cross-sectional geometry of the part being built. On the completion of one print layer, the build platform descends incrementally, and a new layer of powder is spread across the surface, repeating the sintering process. This layer-by-layer approach continues until the part is complete. [2]While there are different types of lasers that can be used in the SLS process, one of the most common is Fiber Lasers. These lasers generate light through diodes that pump energy into a fiber optic cable doped with rare-earth elements such as ytterbium. The resulting light typically has a wavelength of about 1,060 nm, which offers high absorption rates in metals and certain polymers. This characteristic makes fiber lasers highly effective for the precision melting of polymer and metal powders. Advantages of fiber lasers in SLS include their excellent beam quality, energy efficiency, and minimal maintenance requirements. [3]When evaluating laser performance in SLS printing, laser spot size is one of the most important specifications. In short, laser spot size (also known as laser beam diameter) is defined as the smallest diameter that a laser can be focused to with a lens. One major reason why laser spot size is so valuable is because it directly influences the laser energy density, which determines the precision and quality of the sintered parts by affecting the melt pool size, depth of penetration into the powder bed, and overall resolution of the final product. Laser energy density is defined as [4]<img src="https://images.wevolver.com/eyJidWNrZXQiOiJ3ZXZvbHZlci1wcm9qZWN0LWltYWdlcyIsImtleSI6ImZyb2FsYS8xNzEzOTU3Mjc2OTk1LVNjcmVlbnNob3QgMjAyNC0wNC0yNCAxMzE0MTYucG5nIiwiZWRpdHMiOnsicmVzaXplIjp7IndpZHRoIjo5NTAsImZpdCI6ImNvdmVyIn19fQ==" style="width: 100%px;" class="fr-fic fr-dib">&nbsp;Where:Eₛ is the laser energy density (J/cm^2)P is the incident laser power (Watts)v is the laser scan speed (cm/s)δ&nbsp;is the laser beam spot size (cm)The laser spot size itself can be defined and calculated in several different ways, but, in the case of SLS printers, spot size is generally defined by the full width at half-maximum (FWHM). Essentially, FWHM quantifies the beam's spread or divergence by measuring the distance between the two points on the intensity profile (a plot of light intensity versus position) at which the intensity falls to half of its peak value. [5]There are many variables that impact the laser beam spot size. Assuming an ideal Gaussian beam, it’s well-defined that the beam width varies as it propagates along its axis. Therefore, the spot size at the focal length is determined by the focal length itself, the smallest radius of the Gaussian beam (i.e., beam waist), and the beam’s wavelength. Based on this, the spot size is mathematically defined as [6]<img src="https://images.wevolver.com/eyJidWNrZXQiOiJ3ZXZvbHZlci1wcm9qZWN0LWltYWdlcyIsImtleSI6ImZyb2FsYS8xNzEzOTU3NTExMjE0LVNjcmVlbnNob3QgMjAyNC0wNC0yNCAxMzE4MjMucG5nIiwiZWRpdHMiOnsicmVzaXplIjp7IndpZHRoIjo5NTAsImZpdCI6ImNvdmVyIn19fQ==" style="width: 100%px;" class="fr-fic fr-dib">Where:f is the focal length.Wf&nbsp;is the beam radius focal length (i.e., spot size)λ is the laser wavelengthw₀ is the beam waist<img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1714132304695-o.jpg" style="width: 100%px;" class="fr-fic fr-dib">Figure 1: The propagation of a laser along its axis.Ultimately, the laser spot size is an important factor that influences the resolution of printed components as well as properties like density, strength, and minimum feature size. In essence, the degree of detail an SLS 3D printer can achieve is determined by the laser spot size, and the minimum feature size typically corresponds to the laser spot size.<h2 dir="ltr">Impact of Laser Spot Size on Print Quality</h2>When we talk specifically about resolution in 3D printing, there are two types of resolution to consider: the Z resolution and XY resolution. Z resolution is the vertical resolution that is dependent on the layer thickness of the print (i.e. how finely the recoater can spread each new layer of powder material). XY resolution, for its part, refers to the horizontal resolution of the print and is influenced by both laser spot size and the precision of the laser’s movement. [7]A smaller laser spot size therefore directly corresponds to a higher XY print resolution and enables users to integrate very fine details and intricate features into their 3D prints. SLS 3D printers with smaller laser spots are also better equipped to print parts with superior surface finishes. Smaller laser spot sizes have been shown to decrease layer line height, resulting in less visible layer lines, smoother surfaces, and finer details in the printed objects. [8]&nbsp;Research has found that smaller laser spot sizes markedly enhance the geometrical accuracy of printed tracks. [9] One reason for this is that a small spot size affords precise control over the dimensions of the melt tracks, including their width, height, and depth. As part of this, smaller spot sizes minimize the heat-affected zone around the melt tracks, reducing thermal deformations and residual stresses that can compromise the mechanical integrity of the final product.&nbsp;Adjustments in laser power and scanning speed can significantly influence these parameters, enabling the creation of smoother surfaces and more defined track edges. Precise parameter control helps maintain stable melt pool dynamics, crucial for minimizing defects such as porosity and keyhole formation that degrade print quality.&nbsp;<img src="https://images.wevolver.com/eyJidWNrZXQiOiJ3ZXZvbHZlci1wcm9qZWN0LWltYWdlcyIsImtleSI6ImZyb2FsYS8xNzEzOTU1ODQ4MTcxLTVfRXNjaGJhbF9TTFNDb21wb25lbnQuanBnIiwiZWRpdHMiOnsicmVzaXplIjp7IndpZHRoIjo5NTAsImZpdCI6ImNvdmVyIn19fQ==" style="width: 100%px;" class="fr-fic fr-dib"><h2 dir="ltr" id="isPasted">Sintratec’s Unique Selling Proposition (USP)</h2>Sintratec places an important emphasis on SLS printer laser spot size. The company’s machines boast some of the finest laser spot diameters and resolutions in the SLS 3D printing market today. The company’s newest fusion module for its All-Material Platform, the Sintratec S3, is equipped with a 30-watt fiber laser that is focused down to a spot size of just 145 μm. The S2, fitted with a 10-watt fiber laser, has the same laser spot size.&nbsp;Sintratec’s laser spot diameter is substantially smaller than many other SLS platforms on the market. This opens applications for its technology in industries like aerospace and electronics that require not only high throughput and process consistency but also high resolution and part accuracy. You can find a comparison of some leading SLS systems below:<table style="width: 100%;"><tbody><tr><td style="width: 50.0000%;">SLS 3D Printer </td><td style="width: 50.0000%;">Laser Spot Size (μm) </td></tr><tr><td style="width: 50.0000%;">Sintratec S3 and S2 </td><td style="width: 50.0000%;">145 μm [10] </td></tr><tr><td style="width: 50.0000%;">Prodways Promaker P1000 </td><td style="width: 50.0000%;">450 μm [11] </td></tr><tr><td style="width: 50.0000%;">Sinterit Lisa X </td><td style="width: 50.0000%;">650 μm [12] </td></tr><tr><td style="width: 50.0000%;">Formlabs Fuse 1 </td><td style="width: 50.0000%;">200 μm [13] </td></tr></tbody></table><h2 dir="ltr" id="isPasted">Real-World Applications and Benefits</h2>Adopters in various industries are already reaping the benefits of Sintratec’s high-resolution SLS solutions. Around the globe, its Swiss-made systems are leveraged by product developers, engineers, and researchers to create precise, functional prototypes that not only closely match the exact dimensions and shape of final parts, but also their mechanical properties. This application dramatically speeds up design validation and prototype testing, enabling users to move quickly and confidently into series production.<a href="https://sintratec.com/additive-manufacturing-sparks-innovation/" target="_blank">Kontakt-Simon SA</a>, a major manufacturer of electric installation equipment, has been using the Sintratec S2 since 2022 to create complex, high-precision prototypes for the electrical sector. The accuracy of Sintratec’s fiber laser system has been vital in this application because printed parts are used to validate geometries and assemblies before moving into full-scale production. The high-quality surface finish of Sintratec prints, as well as the ability to produce complex shapes with fine details, has been important to Kontakt-Simon, since electric housings and components must not only fit electrical components of varying geometries within them but also fit perfectly into larger assemblies. When asked about the main benefits of the S2, Thomas Wilk, Head of Kontakt-Simon’s technical department, listed “complex geometries, thin walls, high aesthetics and accuracy, great strength, and homogeneity in each axis of the part.”<img src="https://images.wevolver.com/eyJidWNrZXQiOiJ3ZXZvbHZlci1wcm9qZWN0LWltYWdlcyIsImtleSI6ImZyb2FsYS8xNzEzOTU2MDE1NjA3LTZfS29udGFrdFNpbW9uX1NMU0NvbXBvbmVudC5qcGciLCJlZGl0cyI6eyJyZXNpemUiOnsid2lkdGgiOjk1MCwiZml0IjoiY292ZXIifX19" style="width: 100%px;" class="fr-fic fr-dib">Swiss window maker <a href="https://sintratec.com/innovative-window-systems-with-sls-components/" target="_blank">Eschbal</a> has also integrated the Sintratec S2 for a number of end uses, including prototyping, tooling, and small series production parts. Like Kontakt-Simon, the company values the technology’s ability to print parts that closely match the properties of injection molded parts. “With the SLS process, we were especially impressed by the tolerances of up to 0.1 millimeters and the surface quality,” comments Michael Ebnöther, a member of Eschbal’s tech department. For tooling and end-use parts, mechanical properties are paramount. For example, Eschbal optimized a connector component through SLS 3D printing, reducing the weight of the final part by 33%.&nbsp;The case studies represent just a small fraction of the ways that Sintratec’s high-resolution 3D printers are being used. You can find more <a href="https://sintratec.com/stories/" target="_blank">customer stories</a> here.<h2 dir="ltr" id="isPasted">Conclusion</h2>Overall, laser spot size is an important piece of the SLS puzzle, influencing print properties like resolution. By focusing on precision through laser spot size, Sintratec has carved out a position for itself in the broader SLS market that caters to applications that require high print accuracy and fine details. In combination with SLS’ excellent throughput and consistency, the ability to achieve smaller features and ultimately better-quality prints takes the technology to another level.&nbsp;<h2 dir="ltr" id="isPasted">References</h2>1. Awad A, Fina F, Goyanes A, Gaisford S, Basit AW. 3D printing: Principles and pharmaceutical applications of selective laser sintering. Int J Pharm. 2020 Aug 30;586:119594. doi: 10.1016/j.ijpharm.2020.119594. Epub 2020 Jul 2. PMID: 32622811.2. David L. Bourell, Trevor J. Watt, David K. Leigh, Ben Fulcher, Performance Limitations in Polymer Laser Sintering,Physics Procedia, Volume 56, 2014, Pages 147-156, ISSN 1875-3892, https://doi.org/10.1016/j.phpro.2014.08.157.3. Liao, H, Le, MT, &amp; Long, DV. "Optimization on Selective Fiber Laser Sintering of Bimetallic Powder via Design of Experiments Method." Proceedings of the ASME/ISCIE 2012 International Symposium on Flexible Automation. ASME/ISCIE 2012 International Symposium on Flexible Automation. St. Louis, Missouri, USA. June 18–20, 2012. pp. 475-482. ASME. https://doi.org/10.1115/ISFA2012-72324. Lü, L., Fuh, J.Y.H., Wong, Y.S. (2001). Selective Laser Sintering. In: Laser-Induced Materials and Processes for Rapid Prototyping. Springer, Boston, MA. https://doi.org/10.1007/978-1-4615-1469-5_55. J. Chalupský, J. Krzywinski, L. Juha, V. Hájková, J. Cihelka, T. Burian, L. Vyšín, J. Gaudin, A. Gleeson, M. Jurek, A. Khorsand, D. Klinger, H. Wabnitz, R. Sobierajski, M. Störmer, K. Tiedtke, and S. Toleikis, "Spot size characterization of focused non-Gaussian X-ray laser beams," Opt. Express &nbsp;18, 27836-27845 (2010).6. Oz Livneh, Gadi Afek, and Nir Davidson, "Producing an efficient, collimated, and thin annular beam with a binary axicon," Appl. Opt. 57, 3205-3208 (2018)7. Anketa Jandyal, Ikshita Chaturvedi, Ishika Wazir, Ankush Raina, Mir Irfan Ul Haq, 3D printing – A review of processes, materials and applications in industry 4.0, Sustainable Operations and Computers, Volume 3, 2022, Pages 33-42, ISSN 2666 4127, <a href="https://doi.org/10.1016/j.susoc.2021.09.004" target="_blank">https://doi.org/10.1016/j.susoc.2021.09.004</a>.8. M. Launhardt, A. Wörz, A. Loderer, T. Laumer, D. Drummer, T. Hausotte, M. Schmidt, Detecting surface roughness on SLS parts with various measuring techniques, <a href="https://www.sciencedirect.com/science/article/abs/pii/S0142941816302057" target="_blank">https://www.sciencedirect.com/science/article/abs/pii/S0142941816302057</a>9. Vaglio E, De Monte T, Lanzutti A, Totis G, Sortino M, Fedrizzi L. Single tracks data obtained by selective laser melting of Ti6Al4V with a small laser spot diameter. Data Brief. 2020 Oct 22;33:106443. doi: 10.1016/j.dib.2020.106443. PMID: 33195769; PMCID: PMC7642809.10. <a href="https://sintratec.com/sls-3d-printer/amp/sintratec-s2/" target="_blank">https://sintratec.com/sls-3d-printer/amp/sintratec-s2/</a>11. <a href="https://www.prodways.com/wp-content/uploads/2021/09/ProMaker-P1000-Series-EN-V19.08.2021.pdf" target="_blank" data-lf-fd-inspected-kn9eq4roawkarlvp="true">https://www.prodways.com/wp-content/uploads/2021/09/ProMaker-P1000-Series-EN-V19.08.2021.pdf</a>12. https://www.3d-printer.com/3D_Printers/Sinterit_Printers/lisa-x13. https://formlabs.com/3d-printers/fuse-1/tech-specs/

Sintratec's high-precision lasers with smaller spot sizes allow for superior print resolution and finer details in SLS 3D printing.

Sintratec's Laser Spot Size The Key to Superior Print Resolution

Researchers from ITMO University have suggested a method of creating colored patterns with an affordable, domestically-produced laser. Compared to others, the new method makes it possible to create smaller separate patterns within a single bigger one, which are harder to forge. The technology, described in an article <a href="https://www.sciencedirect.com/science/article/pii/S0030399224001002?dgcid=coauthor" target="_blank" id="isPasted">published</a> in Optics and Laser Technology, will help prevent production of counterfeit glass products, such as medical vials and test tubes. &nbsp;Each material has a different nanorelief (irregularities, protrusions, or cavities on the surface) that affects its optical properties. For instance, one surface is better at harvesting and reflecting light, while another will have a limited emissivity. Each property has its own applications: materials with a light-harvesting nanorelief are used in solar cells, while reflective surfaces are used to create iridescent patterns that protect products from counterfeiting.Typically, photolithography is used to create ordered nanoreliefs. This method is reminiscent of using spray paint with a stencil: first, a template is made for the target image; then, it is recreated on a material by shining a laser through the template. However, photolithographs are expensive and require a lot of expendable materials, such as templates and photoresists (materials that react with laser radiation to register an image). Moreover, with this technique, it is impossible to change the image when writing is in progress – instead, that would require an all-new template.&nbsp;An alternative technique is direct writing with scanning laser beams. It doesn’t require expensive equipment or expendable materials, while also being capable of creating smaller structures, as if drawn by a thin brush. Researchers from ITMO’s <a href="https://en.itmo.ru/en/faculty/121/Institute_of_Laser_Technologies.htm/" target="_blank">Institute of Laser Technologies</a> have further improved this approach by introducing a method for generating laser-induced periodic surface structures (LIPSSs). The method can be used to distinguish, print, and combine even smaller nanostructures within the scanning area.&nbsp;<blockquote>“As the material has a rough surface, the laser radiation that reaches it diffracts and turns into an electromagnetic wave that spreads along the surface and interacts with incoming laser radiation. As a result, we get a nanorelief in the shape of a protective pattern. Imagine that laser radiation is a wide brush around 55-70 microns in size. And in this brush, different lines are created by filament, each just 0.7 micrometers in size – that’s 100 times thinner than a human hair. These filaments create tiny nanostructures inside the big structure,” explains&nbsp;Dmitry Sinev, an associate professor at the Institute of laser Technologies.</blockquote><img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1710979599139-ezgif-5-e850060be5.gif" style="width: 100%px;" class="fr-fic fr-dib">Protective trademarks formed via direct writing of laser-induced periodic surface structures. Video courtesy of Dmitry SinevThe new method works as follows: a titanium film is placed upon a glass substrate; then, the film is treated with a laser beam that creates a one-dimensional nanorelief in the shape of several lines. In order to make the geometry more complex and turn the image into a 2D one, the process of forming lines is repeated, with a new set of lines drawn across the first one. The final nanorelief is reminiscent of honeycombs and squares and can be seen in white light, like that from a flashlight.<blockquote>“Through repeated processing, the nanoreliefs took the thermophysical and mechanical properties of the substrate, as well as the optical properties of the film – this changed their interaction with polarized light, as well as refraction and light transmission spectra. Each nanostructure in a pattern shone with different colors of varying intensity based on the angle it was viewed from. Upon request from a customer, we can write any image with additional customization. For instance, we can create a nanostructure that will be brighter at a specific angle, and inform the customer about the configuration parameters. This way, only the customer will know the location of each element and thus will be able to identify the pattern,” adds&nbsp;Alexander Suvorov,, a second-year Master’s student at the Institute of Laser Technologies.</blockquote>According to the paper’s authors, the pattern can be made even more unique if several protective layers are combined in its production: for instance, the image can be writtenin 2D and in 1D.&nbsp;Next, the researchers are planning to use their method to make colorful trademarks that will prevent counterfeiting of medical vials, test tubes, and other products made from transparent materials. Currently, the novel method is capable of printing protective patterns with the resolution of 0.7 microns and the area of 1x1 millimeters in just 18 seconds. In the future, the researchers are planning to increase the writing speed and make the nanostructures smaller, in order to include more elements and make the image even harder to copy.This research project is&nbsp;<a href="https://rscf.ru/project/21-79-10241/" target="_blank">supported</a> by the Russian Science Foundation.

Protective trademarks formed via direct writing of laser-induced periodic surface structures. Photo by Dmitry Grigoryev / ITMO.NEWS

Researchers from ITMO University have suggested a method of creating colored patterns with an affordable, domestically-produced laser. Compared to others, the new method makes it possible to create smaller separate patterns within a single bigger one, which are harder to forge.

A Solution that Prevents Counterfeiting of Glass Products

What happens when you expose tellurite glass to femtosecond laser light? That’s the question that Gözden Torun at the Galatea Lab, in a collaboration with Tokyo Tech scientists, aimed to answer in her thesis work when she made the discovery that may one day turn windows into single material light-harvesting and sensing devices. The results are published in&nbsp;PR Applied.Interested in how the atoms in the tellurite glass would reorganize when exposed to fast pulses of high energy femtosecond laser light, the scientists stumbled upon&nbsp;<a href="https://doi.org/10.1002/adma.202210446" target="_blank" rel="noopener">the formation of nanoscale tellurium and tellurium oxide crystals</a>, both semiconducting materials etched into the glass, precisely where the glass had been exposed. That was the eureka moment for the scientists, since a semiconducting material exposed to daylight may lead to the generation of electricity.“Tellurium being semiconducting, based on this finding we wondered if it would be possible to write durable patterns on the tellurite glass surface that could reliably induce electricity when exposed to light, and the answer is yes,” explains Yves Bellouard who runs EPFL’s Galatea Laboratory. “An interesting twist to the technique is that no additional materials are needed in the process. All you need is tellurite glass and a femtosecond laser to make an active photoconductive material.”Using tellurite glass produced by colleagues at Tokyo Tech, the EPFL team brought their expertise in femtosecond laser technology to modify the glass and analyze the effect of the laser. After exposing a simple line pattern on the surface of a tellurite glass 1 cm in diameter, Torun found that it could generate a current when exposing it to UV light and the visible spectrum, and this, reliably for months.“It’s fantastic, we’re locally turning glass into a semiconductor using light,” says Yves Bellouard. “We’re essentially transforming materials into something else, perhaps approaching the dream of the alchemist!”.<hr>References<a href="https://journals.aps.org/prapplied/abstract/10.1103/PhysRevApplied.21.014008" target="_blank" rel="noopener">https://journals.aps.org/prapplied/abstract/10.1103/PhysRevApplied.21.014008</a>

A photoconductive circuit, where the circuit is directly patterned onto a glass surface with femtosecond laser light - 2024 EPFL / Lisa Ackermann - CC-BY-SA 4.0

EPFL physicists propose a novel way to create photoconductive circuits, where the circuit is directly patterned onto a glass surface with femtosecond laser light. The new technology may one day be useful for harvesting energy, while remaining transparent to light and using a single material.

Turning glass into a 'transparent' light-energy harvester

The progression of laser additive manufacturing — which involves 3D printing of metallic objects using powders and lasers — has often been hindered by unexpected defects. Traditional monitoring methods, such as thermal imaging and machine learning algorithms, have shown significant limitations. They often either overlook defects or misinterpret them, making precision manufacturing elusive and barring the technique from essential industries like aeronautics and automotive manufacturing. But what if it were possible to detect defects in real time based on the differences in the sound the printer makes during a flawless print and one with irregularities? Up until now, the prospect of detecting these defects this way was deemed unreliable. However, researchers at the Laboratory of Thermomechanical Metallurgy (<a href="https://www.epfl.ch/labs/lmtm/" target="_blank">LMTM</a>) at EPFL's School of Engineering have successfully challenged this assumption.<blockquote>There's been an ongoing debate regarding the viability and effectiveness of acoustic monitoring for laser-based additive manufacturing. Our research not only confirms its relevance but also underscores its advantage over traditional methods.<footer>Professor Roland Logé, Head of the Laboratory of Thermomechanical Metallurgy</footer></blockquote>Professor Roland Logé, the head of the laboratory, stated, "There's been an ongoing debate regarding the viability and effectiveness of acoustic monitoring for laser-based additive manufacturing. Our research not only confirms its relevance but also underscores its advantage over traditional methods."This research is of paramount importance to the industrial sector as it introduces a groundbreaking, yet cost-effective solution to monitor and improve the quality of products made through Laser Powder Bed Fusion (LPBF). Lead researcher, Dr. Milad Hamidi Nasab, remarked, "The synergy of synchrotron X-ray imaging with acoustic recording provides real-time insight into the LPBF process, facilitating the detection of defects that could jeopardize product integrity." In an era where industries continuously strive for efficiency, precision, and waste reduction, these innovations not only result in significant cost savings but also boost the dependability and security of manufactured products.<h2>How Does LPBF Manufacturing Work?</h2>LPBF is a cutting-edge method that's reshaping metal manufacturing. Essentially, it uses a high-intensity laser to meticulously melt minuscule metal powders, creating layer upon layer to produce detailed 3D metallic constructs. Think of LPBF as the metallic version of a conventional 3D printer, but with an added degree of sophistication. Rather than melted plastic, it employs a fine layer of microscopic metal powder, which can vary in size from the thickness of a human hair to a fine grain of salt (15–100 μm). The laser moves across this layer, melting specific patterns based on a digital blueprint. This technique enables the crafting of bespoke, complex parts like lattice structures or distinct geometries, with minimal excess. Nevertheless, this promising method isn't devoid of challenges.When the laser interacts with the metal powder, creating what is known as a melt pool, it fluctuates between liquid, vapor, and solid phases. Occasionally, due to variables such as the laser's angle or the presence of specific geometrical attributes of the powder or of the part, the process might falter. These instances, termed "inter-regime instabilities", can sometimes prompt shifts between two melting methods, known as "conduction" and "keyhole" regimes. During unstable keyhole regimes, when the molten powder pool delves deeper than intended, it can create pockets of porosity, culminating in structural flaws in the end product. To facilitate the measurement of the width and depth of the melt pool in X-ray images, the Image Analysis Hub of the EPFL Center for Imaging developed an approach that makes it easier to visualize small changes associated with the liquid metal and a tool for annotating the melt pool geometry.<img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1705050644241-5311e230.jpg" style="width: 300px;" class="fr-fic fr-dib">A graphic representation of the exeperimental setup for listening for printing defects - 2023 EPFL / Titouan Veuillet - CC-BY-SA 4.0<h2 id="isPasted">Detecting These Defects Using Sound</h2>In a joint venture with the Paul Scherrer Institute (PSI) and the Swiss Federal Laboratories for Materials Science and Technology (Empa), the EPFL team formulated an experimental design that melded operando X-ray imaging experiments with acoustic emission measurements. The experiments were conducted at the TOMCAT beamline of the Swiss Light Source at PSI, with the miniaturized LPBF printer developed in the group of Dr. Steven Van Petegem. The amalgamation with an ultra-sensitive microphone, positioned inside the printing chamber, pinpointed distinct shifts in the acoustic signal during regime transitions, thereby directly identifying defects during manufacturing.A pivotal moment in the research was the introduction of an adaptive filtering technique by signal processing expert Giulio Masinelli from Empa. "This filtering approach," Masinelli emphasized, " allows us to discern, with unparalleled clarity, the relationship between defects and the accompanying acoustic signature." Unlike typical machine learning algorithms, which excel at extracting patterns from statistical data, but are often tailored to specific scenarios, this approach provides broader insights on the physics of melting regimes, while offering superior temporal and spatial precision.With this research, EPFL contributes valuable insights to the field of laser additive manufacturing. The findings have significant implications for potential industrial applications, particularly in sectors like aerospace and precision engineering. Reinforcing Switzerland's reputation for meticulous craftsmanship and manufacturing accuracy, the study underscores the need for consistent manufacturing techniques. Furthermore, it suggests the potential for early detection and correction of defects, enhancing product quality. Professor Logé concludes, "This research paves the way for a better understanding and refinement of the manufacturing process, and will ultimately lead to higher product reliability in the long term."<hr>ReferencesHamidi Nasab, M., Masinelli, G., de Formanoir, C., Schlenger, L., Van Petegem, S., Esmaeilzadeh, R., Wasmer, K., Ganvir, A., Salminen, A., Aymanns, F., Marone, F., Pandiyan, V., Goel, S., &amp; Logé, R. (2023). Harmonizing Sound and Light: X-Ray Imaging Unveils Acoustic Signatures of Stochastic Inter-Regime Instabilities during Laser Melting . Nature Communications. DOI:&nbsp;<a href="https://www.nature.com/articles/s41467-023-43371-3" rel="noopener" target="_blank">10.1038/s41467-023-43371-3</a>

A graphic representation of the exeperimental setup for listening for printing defects - 2023 EPFL / Titouan Veuillet - CC-BY-SA 4.0

Researchers from EPFL have resolved a long-standing debate surrounding laser additive manufacturing processes with a pioneering approach to defect detection.

Laser additive manufacturing: listening for defects as they happen

In a study published Nov. 24 in&nbsp;<a href="https://www.nature.com/articles/s41467-023-43501-x" rel="nofollow" target="_blank">Nature Communications</a>,&nbsp;<a href="https://www.engineering.columbia.edu/" rel="nofollow" target="_blank">Columbia Engineering</a> researchers and collaborators at the&nbsp;<a href="https://www.mpsd.mpg.de/en" rel="nofollow" target="_blank">Max Planck Institute for the Structure and Dynamics of Matter</a> find that pairing laser light to crystal lattice vibrations can enhance the nonlinear optical properties of a layered 2D material. The finding could lead to new ways of using light to modify materials.Cecilia Chen, a Columbia Engineering PhD student and co-author of the paper,&nbsp;and her colleagues from the&nbsp;<a href="https://gaeta.apam.columbia.edu/" rel="nofollow" target="_blank">Quantum and Nonlinear Photonics group</a>, led by&nbsp;<a href="https://www.apam.columbia.edu/faculty/alex-gaeta" rel="nofollow" target="_blank">Alexander Gaeta</a>, David M. Rickey Professor of&nbsp;<a href="https://www.apam.columbia.edu/" rel="nofollow" target="_blank">Applied Physics</a> and Materials Science, used hexagonal boron nitride (hBN). A 2D material similar to graphene, hBN’s atoms are arranged in a honey-combed-shaped repeating pattern and can be peeled into thin layers with unique quantum properties. Chen noted that hBN is stable at room temperature, and its constituent elements—boron and nitrogen—are very light. That means they vibrate very quickly.Atomic vibrations occur in all materials above absolute zero. That movement can be quantized into quasiparticles called phonons with particular resonances; in hBN's case, the team was interested in the optical phonon mode corresponding to a wavelength of 7.3 μm, in the mid-infrared regime of the electromagnetic spectrum. While mid-IR wavelengths are considered short, and thus, high energy, in the picture of crystal vibrations, they are considered very long and low energy in most optics research, where the overwhelming majority of experiments and studies are performed in the visible to near-IR range of approximately 400 nm to 2 um.When they tuned their laser system to hBN’s frequency, 7.3 μm, Chen, along with Jared Ginsberg PhD’21 (now a data scientist at Bank of America) and postdoc Mehdi Jadidi (now a team lead at PsiQuantum), were able to coherently drive the resonance of the hBN crystal and generate new optical frequencies from the medium—a goal of nonlinear optics. Theoretical work led by&nbsp;<a href="https://www.mpsd.mpg.de/person/39745/2736" rel="nofollow" target="_blank">Angel Rubio’s group</a> at Max Planck helped the experimental team understand their results.Using commercially available, table-top mid-infrared lasers, they explored the phonon-mediated four-wave mixing around even harmonic orders. The crystal could withstand up to 10% atomic displacement without damage. They also observed a 30-fold increase in third-harmonic generation.“We’re excited to show that amplifying the natural phonon motion with laser driving can enhance nonlinear optical effects and generate new frequencies,” said Chen. In future work, the team plans to explore how to modify hBN and materials like it using light.

The Gaeta lab used near-infrared light to drive particles in a crystal of hexagonal boron nitride, generating new optical frequencies. Credit: 420494 from Pixabay

Columbia Engineers pair vibrating particles, called phonons, with particles of light, called photons, to enhance the nonlinear optical properties of hexagonal boron nitride. The finding could lead to new ways of using light to modify materials. Learn more.

Laser-driving a 2D Material

The team at EPFL’s <a href="https://phosl.epfl.ch/" target="_blank">Photonic Systems Laboratory</a> (PHOSL) has developed a chip-scale laser source that enhances the performance of semiconductor lasers while enabling the generation of shorter wavelengths. This pioneering work, led by Professor Camille Brès and postdoctoral researcher Marco Clementi from EPFL’s School of Engineering represents a significant advance in the field of photonics, with implications for telecommunications, metrology, and other high-precision applications.The study, published in the journal Light: Science &amp; Applications, reveals how the PHOSL researchers, in collaboration with the <a href="https://www.epfl.ch/labs/k-lab/" target="_blank">Laboratory of Photonics and Quantum Measurements</a>, have successfully integrated semiconductor lasers with silicon nitride photonic circuits containing microresonators. This integration results in a hybrid device capable of emitting highly uniform and precise light in both near-infrared and visible ranges, filling a technological gap that has long challenged the industry."Semiconductor lasers are ubiquitous in modern technology, found in everything from smartphones to fiber optic communications. However, their potential has been limited by a lack of coherence and the inability to generate visible light efficiently," explains Professor Brès . "Our work not only improves the coherence of these lasers but also shifts their output towards the visible spectrum, opening up new avenues for their use."Coherence, in this context, refers to the uniformity of the phases of the light waves emitted by the laser. High coherence means the light waves are synchronized, leading to a beam with a very precise color or frequency. This property is crucial for applications where precision and stability of the laser beam are paramount, such as time keeping and precision sensing.Increased accuracy and improved functionality The team's approach involves coupling commercially available semiconductor lasers with a silicon nitride chip. This tiny chip is created with industry-standard, cost-efficient CMOS technology. Thanks to the material’s exceptional low-loss properties, there is little to no light that is absorbed or escapes. The light from the semiconductor laser flows through microscopic waveguides into extremely small cavities, where the beam is trapped. These cavities, called micro-ring resonators, are intricately designed to resonate at specific frequencies, selectively amplifying the desired wavelengths while attenuating others, thereby achieving enhanced coherence in the emitted light.The other significant achievement is the hybrid system’s ability to double the frequency of the light coming from the commercial semiconductor laser— enabling a shift from the near-infrared spectrum to the visible light spectrum. The relationship between frequency and wavelength is inversely proportional, meaning that if the frequency is doubled, the wavelength is reduced by half. While the near infrared spectrum is exploited for telecommunications, higher frequencies are essential for building smaller, more efficient devices where shorter wavelengths are needed, such as in atomic clocks and medical devices.These shorter wavelengths are achieved when the trapped light in the cavity undergoes a process called all-optical poling, which induces what is known as second-order nonlinearity in the silicon nitride. Nonlinearity in this context means that there is a significant shift, a jump in magnitude, in the light's behavior that is not directly proportional to its frequency, arising from its interaction with the material. Silicon nitride does not normally incur this specific second order nonlinear effect, and the team performed an elegant engineering feat to induce it: The system takes advantage of the light’s capacity, when resonating within the cavity, to produce an electromagnetic wave that provokes the nonlinear properties in the material.<h2>An enabling technology for future applications</h2>"We are not just improving existing technology but also pushing the boundaries of what's possible with semiconductor lasers," says Marco Clementi, who played a key role in the project. "By bridging the gap between telecom and visible wavelengths, we're opening the door to new applications in fields like biomedical imaging and precision timekeeping."<img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1703080828384-ezgif-2-416faa76dd.jpg" style="width: 300px;" class="fr-fic fr-dib">Professor Camille Brès and Marco Clementi in the lab. - 2023 EPFL/Alain Herzog - CC-BY-SA 4.0One of the most promising applications of this technology is in metrology, particularly in the development of compact atomic clocks. The history of navigational advancements hinges on the portability of accurate timepieces—from determining longitude at sea in the 16th Century to ensuring the accurate navigation of space missions and achieving better geo-localization today. "This significant advancement lays the groundwork for future technologies, some of which are yet to be conceived," notes Clementi.The team’s deep understanding of photonics and material science will potentially lead to smaller and lighter devices and lower the energy consumption and production costs of lasers. Their ability to take a fundamental scientific concept and translate it into a practical application using industry standard fabrication underscores the potential of solving complex technological challenges that can lead to unforeseen advances.<hr>ReferencesClementi, M., Nitiss, E., Durán-Valdeiglesias, E., Belahsene, S., Liu, J., Kippenberg, T. J., Debrégeas, H., &amp; Brès, C.-S. (2023). A chip-scale second-harmonic source via injection-locked all-optical poling. Light: Science &amp; Applications.&nbsp;<a href="https://doi.org/10.1038/s41377-023-01329-6" title="https://doi.org/10.1038/s41377-023-01329-6" target="_blank" rel="noopener">https://doi.org/10.1038/s41377-023-01329-6</a>

The micro-resonator being activated by a semi-conductor laser. - 2023 EPFL/Alain Herzog - CC-BY-SA 4.0

EPFL researchers have developed a hybrid device that significantly improves existing, ubiquitous laser technology.

A micro-ring resonator with big potential

New research from the lab of Caltech's&nbsp;<a href="https://www.eas.caltech.edu/people/lvw" target="_blank">Lihong Wang</a>, the Bren Professor of Medical Engineering and Electrical Engineering, is the latter. In a paper published in the journal&nbsp;Nature Biomedical Engineering, Wang and postdoctoral scholar Yide Zhang show how they have simplified and improved&nbsp;<a href="https://www.caltech.edu/about/news/advancement-simplifies-laser-based-medical-imaging" target="_blank">an imaging technique</a> they first announced in 2020.That technique, a form of photoacoustic imaging technology called PATER (Photoacoustic Topography Through an Ergodic Relay), is a specialty of Wang's group.In photoacoustic imaging, laser light is pulsed into tissue where it is absorbed by the tissue's molecules, causing them to vibrate. Each vibrating molecule serves as a source of ultrasonic waves that can be used to image the internal structures in a fashion similar to how ultrasound imaging is performed.However, photoacoustic imaging is technologically challenging because it produces all its imaging information in one short burst. To capture that information, early versions of Wang's photoacoustic imaging technology required arrays of hundreds of sensors (transducers) to be pressed against the surface of the tissue being imaged, which made the technology complicated and expensive.Wang and Zhang reduced the number of required transducers by using a device called an ergodic relay, which slows down the rate at which information (in the form of vibrations) flows into a transducer. As explained in a&nbsp;<a href="https://www.caltech.edu/about/news/advancement-simplifies-laser-based-medical-imaging" target="_blank">previous story</a> about PATER:In computing, there are two main ways to transmit data: serial and parallel. In serial transmission, the data are sent in a single stream through one communication channel. In parallel transmission, several pieces of data are sent at the same time using multiple communication channels.The two types of communication are roughly analogous to the way cash registers might be used in a store. Serial communication would be like having one cash register. Everyone gets in the same line and sees the same cashier. Parallel communication would be like having several registers and a line for each.The system Wang designed with 512 sensors is similar to the store with many cash registers. All of the sensors are working at the same time, with each taking in part of the data about the ultrasonic vibrations generated by the laser pulse.Since the ultrasonic vibrations from the system come in one short burst, a single sensor would be overwhelmed if it were used to try and collect all the data in that short amount of time. That's where the ergodic relay comes in.As Wang describes it, an ergodic relay is a sort of chamber around which sound can echo. When the ultrasonic vibrations pass through the ergodic relay, they are stretched out in time. To return to the cash-register metaphor, it would be like having another employee assisting the single cashier by telling the customers to walk a few laps around the store until the cashier is ready to see them, so the cashier does not become overwhelmed.The latest version of this technology, called PACTER (Photoacoustic Computed Tomography Through an Ergodic Relay) goes even further, allowing the system to operate using a single transducer that, through the use of software, can collect as much data as 6,400 transducers.<iframe width="640" height="360" src="https://www.youtube.com/embed/L7r5eNtaLq4?&amp;wmode=opaque&amp;rel=0&amp;enablejsapi=1&amp;origin=https://www.wevolver.com" frameborder="0" allowfullscreen="" class="fr-draggable" data-lf-vimeo-playback-inspected-kn9eq4roawkarlvp="true" data-lf-yt-playback-inspected-kn9eq4roawkarlvp="true" data-lf-form-tracking-inspected-kn9eq4roawkarlvp="true"></iframe>PACTER improves on PATER in two other ways, says Wang, who is also the Andrew and Peggy Cherng Medical Engineering Leadership Chair and executive officer for medical engineering.One improvement is that PACTER can create three-dimensional images, whereas PATER can only generate 2D images. This was enabled by the development of improved software."Transitioning to 3D imaging significantly escalates the data requirement. The challenge was funneling the immensely increased data through a single transducer," Zhang says. "Our solution emerged by altering our approach. Rather than a direct and computationally intensive method of reconstructing 3-D images from the single-transducer data, we first expanded one transducer into thousands of virtual ones. This idea simplified the process of 3D image reconstruction, aligning it more closely with the traditional methods in our photoacoustic imaging."Secondly, unlike PATER, PACTER does not need to be calibrated each time it is used."With PATER, we had to calibrate it each time to use it and that's just not practical. We got rid of this per-use single-time calibration," Wang says.Calibration was needed because when the system fires a pulse of laser light into tissue, an "echo" of that pulse would bounce back into the transducer, preventing it from sensing direct ultrasound information.Wang says PACTER gets around that issue by adding something called a delay line to the system. The delay line forces the echo to take a longer physical path on its way back to the transducer so that it arrives after the direct ultrasound information has been received."Even though I always said this was possible, I knew it would be challenging," Wang says.The paper describing the work, "Ultrafast longitudinal imaging of haemodynamics via single-shot volumetric photoacoustic tomography with a single-element detector," appears in the November 30 issue of&nbsp;Nature Biomedical Engineering. Co-authors are Peng Hu (PhD '23), former graduate student in medical engineering; Lei Li (PhD '19), former postdoc in medical engineering; Rui Cao, postdoc in medical engineering; Anjul Khadria, former postdoc in medical engineering; Konstantin Maslov, former staff scientist at Caltech; Xin Tong, graduate student in medical engineering; and Yushun Zeng, Laiming Jiang, and Qifa Zhou of USC.

There are times when scientific progress comes in the form of discovering something completely new. Other times, progress boils down to doing something better, faster, or more easily.

Advancements Make Laser-Based Imaging Simpler and Three-Dimensional

The practice of keeping time hinges on stable oscillations. In a grandfather clock, the length of a second is marked by a single swing of the pendulum. In a digital watch, the vibrations of a quartz crystal mark much smaller fractions of time. And in atomic clocks, the world’s state-of-the-art timekeepers, the oscillations of a laser beam stimulate atoms to vibrate at 9.2 billion times per second. These smallest, most stable divisions of time set the timing for today’s satellite communications, GPS systems, and financial markets.A clock’s stability depends on the noise in its environment. A slight wind can throw a pendulum’s swing out of sync. And heat can disrupt the oscillations of atoms in an atomic clock. Eliminating such environmental effects can improve a clock’s precision. But only by so much.A new MIT study finds that even if all noise from the outside world is eliminated, the stability of clocks, laser beams, and other oscillators would still be vulnerable to quantum mechanical effects. The precision of oscillators would ultimately be limited by quantum noise.But in theory, there’s a way to push past this quantum limit. In their study, the researchers also show that by manipulating, or “squeezing,” the states that contribute to quantum noise, the stability of an oscillator could be improved, even past its quantum limit.“What we’ve shown is, there’s actually a limit to how stable oscillators like lasers and clocks can be, that’s set not just by their environment, but by the fact that quantum mechanics forces them to shake around a little bit,” says Vivishek Sudhir, assistant professor of mechanical engineering at MIT. “Then, we’ve shown that there are ways you can even get around this quantum mechanical shaking. But you have to be more clever than just isolating the thing from its environment. You have to play with the quantum states themselves.”The team is working on an experimental test of their theory. If they can demonstrate that they can manipulate the quantum states in an oscillating system, the researchers envision that clocks, lasers, and other oscillators could be tuned to super-quantum precision. These systems could then be used to track infinitesimally small differences in time, such as the fluctuations of a single qubit in a quantum computer or the presence of a dark matter particle flitting between detectors.“We plan to demonstrate several instances of lasers with quantum-enhanced timekeeping ability over the next several years,” says Hudson Loughlin, a graduate student in MIT’s Department of Physics. “We hope that our recent theoretical developments and upcoming experiments will advance our fundamental ability to keep time accurately, and enable new revolutionary technologies.”Loughlin and Sudhir detail their work in an open-access&nbsp;<a href="https://www.nature.com/articles/s41467-023-42739-9" target="_blank">paper published in the journal&nbsp;Nature Communications</a>.<h2>Laser precision</h2>In studying the stability of oscillators, the researchers looked first to the laser — an optical oscillator that produces a wave-like beam of highly synchronized photons. The invention of the laser is largely credited to physicists Arthur Schawlow and Charles Townes, who coined the name from its descriptive acronym: light amplification by stimulated emission of radiation.A laser’s design centers on a “lasing medium” — a collection of atoms, usually embedded in glass or crystals. In the earliest lasers, a flash tube surrounding the lasing medium would stimulate electrons in the atoms to jump up in energy. When the electrons relax back to lower energy, they give off some radiation in the form of a photon. Two mirrors, on either end of the lasing medium, reflect the emitted photon back into the atoms to stimulate more electrons, and produce more photons. One mirror, together with the lasing medium, acts as an “amplifier” to boost the production of photons, while the second mirror is partially transmissive and acts as a “coupler” to extract some photons out as a concentrated beam of laser light.Since the invention of the laser, Schawlow and Townes put forth a hypothesis that a laser’s stability should be limited by quantum noise. Others have since tested their hypothesis by modeling the microscopic features of a laser. Through very specific calculations, they showed that indeed, imperceptible, quantum interactions among the laser’s photons and atoms could limit the stability of their oscillations.“But this work had to do with extremely detailed, delicate calculations, such that the limit was understood, but only for a specific kind of laser,” Sudhir notes. “We wanted to enormously simplify this, to understand lasers and a wide range of oscillators."<h2>Putting the “squeeze” on</h2>Rather than focus on a laser’s physical intricacies, the team looked to simplify the problem.“When an electrical engineer thinks of making an oscillator, they take an amplifier, and they feed the output of the amplifier into its own input,” Sudhir explains. “It’s like a snake eating its own tail. It’s an extremely liberating way of thinking. You don’t need to know the nitty gritty of a laser. Instead, you have an abstract picture, not just of a laser, but of all oscillators.”In their study, the team drew up a simplified representation of a laser-like oscillator. Their model consists of an amplifier (such as a laser’s atoms), a delay line (for instance, the time it takes light to travel between a laser’s mirrors), and a coupler (such as a partially reflective mirror).The team then wrote down the equations of physics that describe the system’s behavior, and carried out calculations to see where in the system quantum noise would arise.“By abstracting this problem to a simple oscillator, we can pinpoint where quantum fluctuations come into the system, and they come in in two places: the amplifier and the coupler that allows us to get a signal out of the oscillator,” Loughlin says. “If we know those two things, we know what the quantum limit on that oscillator’s stability is.”Sudhir says scientists can use the equations they lay out in their study to calculate the quantum limit in their own oscillators.What’s more, the team showed that this quantum limit might be overcome, if quantum noise in one of the two sources could be “squeezed.” Quantum squeezing is the idea of minimizing quantum fluctuations in one aspect of a system at the expense of proportionally increasing fluctuations in another aspect. The effect is similar to squeezing air from one part of a balloon into another.In the case of a laser, the team found that if quantum fluctuations in the coupler were squeezed, it could improve the precision, or the timing of oscillations, in the outgoing laser beam, even as noise in the laser’s power would increase as a result.“When you find some quantum mechanical limit, there’s always some question of how malleable is that limit?” Sudhir says. “Is it really a hard stop, or is there still some juice you can extract by manipulating some quantum mechanics? In this case, we find that there is, which is a result that is applicable to a huge class of oscillators.”

Clocks, lasers, and other oscillators could be tuned to super-quantum precision, allowing researchers to track infinitesimally small differences in time, according to a new MIT study. Image: MIT News; iStock

More stable clocks could measure quantum phenomena, including the presence of dark matter.

With a quantum "squeeze," clocks could keep even more precise time, MIT researchers propose

In those latter applications, lasers that can emit extremely short pulses—those on the order of one-trillionth of a second (one picosecond) or shorter—are especially useful. Using lasers operating on such small timescales, researchers can study physical and chemical phenomena that occur extremely quickly—for example, the making or breaking of molecular bonds in a chemical reaction or the movement of electrons within materials. These ultrashort pulses are also extensively used for imaging applications because they can have extremely large peak intensities but low average power, so they avoid heating or even burning up samples such as biological tissues.In a paper appearing in the journal Science, Caltech's <a href="https://www.eas.caltech.edu/people/amarandi" target="_blank">Alireza Marandi</a>, an assistant professor of electrical engineering and applied physics, describes a new method developed by his lab for making this kind of laser, known as a mode-locked laser, on a photonic chip. The lasers are made using nanoscale components (a nanometer is one-billionth of a meter), allowing them to be integrated into light-based circuits similar to the electricity-based integrated circuits found in modern electronics."We're not just interested in making mode-locked lasers more compact," Marandi says. "We are excited about making a well-performing mode-locked laser on a nanophotonic chip and combining it with other components. That's when we can build a complete ultrafast photonic system in an integrated circuit. This will bring the wealth of ultrafast science and technology, currently belonging to meter-scale experiments, to millimeter-scale chips."Ultrafast lasers of this sort are so important to research, that this year's Nobel Prize in Physics was awarded to a trio of scientists for the development of lasers that produce attosecond pulses (one attosecond is one-quintillionth of a second). Such lasers, however, are currently extremely expensive and bulky, says Marandi—who notes that his research is exploring methods to achieve such timescales on chips that can be orders of magnitude cheaper and smaller, with the aim of developing affordable and deployable ultrafast photonic technologies."These attosecond experiments are done almost exclusively with ultrafast mode-locked lasers," he says. "And some of them can cost as much as $10 million, with a good chunk of that cost being the mode-locked laser. We are really excited to think about how we can replicate those experiments and functionalities in nanophotonics."At the heart of the nanophotonic mode-locked laser developed by Marandi's lab is lithium niobate, a synthetic salt with unique optical and electrical properties that, in this case, allows the laser pulses to be controlled and shaped through the application of an external radio-frequency electrical signal. This approach is known as active mode-locking with intracavity phase modulation."About 50 years ago, researchers used intracavity phase modulation in tabletop experiments to make mode-locked lasers and decided that it was not a great fit compared to other techniques," says Qiushi Guo, the first author of the paper and a former postdoctoral scholar in Marandi's lab. "But we found it to be a great fit for our integrated platform.""Beyond its compact size, our laser also exhibits a range of intriguing properties. For example, we can precisely tune the repetition frequency of the output pulses in a wide range. We can leverage this to develop chip-scale stabilized frequency comb sources, which are vital for frequency metrology and precision sensing," adds Guo, who is now an assistant professor at the City University of New York Advanced Science Research Center.Marandi says he aims to continue improving this technology so it can operate at even shorter timescales and higher peak powers, with a goal of 50 femtoseconds (a femtosecond is one-quadrillionth of a second), which would be a 100-fold improvement over his current device, which generates pulses 4.8 picoseconds in length.<hr>The paper describing the research is titled "<a href="https://www.science.org/doi/10.1126/science.adj5438" target="_blank">Ultrafast mode-locked laser in nanophotonic lithium niobite</a>" and appears in the November 9 issue of Science. Co-authors are Benjamin K. Gutierrez (MS '23), graduate student in applied physics; electrical engineering graduate students Ryoto Sekine (MS '22), Robert M. Gray (MS '22), James A. Williams, Selina Zhou (BS '22), and Mingchen Liu; Luis Ledezma (PhD '23), an external affiliate in electrical engineering; Luis Costa, formerly at Caltech and now with JPL, which Caltech manages for NASA; and Arkadev Roy (MS '23, PhD '23), formerly of Caltech and now with UC Berkeley .

Lasers have become relatively commonplace in everyday life, but they have many uses outside of providing light shows at raves and scanning barcodes on groceries. Lasers are also of great importance in telecommunications and computing as well as biology, chemistry, and physics research.

Ultrafast Lasers on Ultra-Tiny Chips

Small satellites are becoming increasingly compact and powerful. The technology of conventional radio channels is reaching its limits due to the rising number of satellites. Laser communications offers solutions for the efficient transmission of high data volumes without interfering with other channels. For this application, the German Aerospace Center (Deutsches Zentrum für Luft- und Raumfahrt; DLR) <a href="https://www.dlr.de/en/kn" target="_blank">Institute of Communications and Navigation</a>, together with the company Tesat-Spacecom GmbH &amp; Co. KG <a href="https://www.tesat.de/" target="_blank" rel="noopener noreferrer">TESAT</a>, developed OSIRIS4CubeSat, the world's smallest commercially available laser communications terminal. The reliability and error-free functionality of the terminal, which was specifically developed for use on microsatellites, was confirmed during a test mission in space.<img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1699086525920-image-1600-66c2779f82a779fcbe74aba8d1b6a0ad.jpeg" style="width: 766px;" class="fr-fic fr-dib">The highly compact communication terminal CubeLCT was developed at the DLR Institute of Communication and Navigation on behalf of the company Tesat Spacecom. It is prepared for series production and can be integrated and adjusted with a few degrees of freedom. Credit: DLR (CC BY-NC-ND 3.0)"This success is the result of our many years of research in the field of optical satellite communications," says Florian David, Director of the DLR Institute of Communications and Navigation. "It demonstrates the impressive potential for designing small, light and at the same time powerful optical satellite terminals. This is an important building block for future satellite systems, for example for Earth observation or in megaconstellations."<h2>Microsatellite with an optical communications system</h2>The first OSIRIS4CubeSat terminal was launched into space on board the CubeL satellite on 24 January 2021. During the <a href="https://www.dlr.de/de/aktuelles/nachrichten/2021/01/20210124_pionierstart-kleinsatellit-mit-kleinstem-laserterminal-der-welt" target="_blank">PIXL-1 mission</a>, images acquired by the camera system on CubeL could be sent to the Optical Ground Station Oberpfaffenhofen using the OSIRIS4CubeSat laser. Both the satellite and the laser terminal have since undergone extensive testing. Now the tests have been successfully completed with an end-to-end demonstration. The reliability and error-free functionality of OSIRIS4CubeSat in space have been confirmed.Microsatellites, or CubeSats, have a standardised cube shape with an edge length of 10 centimetres and can be extended as required. The laser communications terminal developed in the <a href="https://www.dlr.de/kn/en/desktopdefault.aspx/tabid-17840/#gallery/36173" target="_blank" rel="noopener noreferrer">OSIRIS4CubeSat</a> project together with TESAT complies with this standard. The patented design, in which an electronic circuit board was used as the mechanical basis for the optical elements for the first time, made it possible to achieve a high degree of compactness.<h2>High data transmission rates without electromagnetic interference</h2>With a data rate of 100 megabits per second, the laser terminal's speed far surpasses the transmission capabilities of comparable radio systems. In addition to the high data rate, laser light as a transmission medium is unaffected by electromagnetic interference. Channel crosstalk, as often occurs with conventional radio channels, does not exist with laser transmission. This means that laser transmission channels do not require lengthy approval procedures on the part of the Federal Network Agency (Bundesnetzagentur; BNetzA) or the International Telecommunication Union (ITU).When transmitting image data to Earth by laser, encoding procedures developed at DLR were employed to safeguard the data. This is necessary to maintain stable, zero-loss transmission from the satellite to Earth, since the data must be protected from disruptions caused by atmospheric effects. For this purpose, they are encoded on the satellite before being sent to the ground station using the laser link. There, following reception, they are decoded and then processed. The <a href="https://www.dlr.de/en/research-and-transfer/projects-and-missions/iss/the-german-space-operations-center" target="_blank">German Space Operations Center (GSOC)</a> is responsible for the commanding, operation and support of the satellite. CubeL is thus the first CubeSat to be successfully integrated into GSOC's existing ground segment.<img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1699086552505-image-1600-a23a7a8f570e1abd2658cf00a0296875.jpeg" style="width: 766px;" class="fr-fic fr-dib">The new op­ti­cal ground sta­tion on the roof of the DLR In­sti­tute of Com­mu­ni­ca­tions and Nav­i­ga­tion in Oberp­faf­fen­hofen. Credit: DLR (CC BY-NC-ND 3.0)<h2>From research to industrial application</h2>The results from PIXL-1 show the error-free functionality of the OSIRIS4CubeSat terminal along the complete transmission chain. This will enable widespread use of laser communications on a large number of satellites in the future. The technology was transferred to TESAT even before the demonstration mission was completed. TESAT has since incorporated the terminal into its portfolio and offers it to commercial customers under the name 'CubeLCT' or 'SCOT20', which is a further development of the product.Siegbert Martin, Chief Technology Officer at TESAT said: "This underlines the great opportunities that arise from cooperation between research and industry in Germany."

The PIXL-1 small satellite can acquire images of the Earth with a high-resolution camera and send them to the Optical Ground Station Oberpfaffenhofen with the CubeLCT via a laser link. Credit: DLR (CC BY-NC-ND 3.0)

Small satellites are becoming increasingly compact and powerful. The technology of conventional radio channels is reaching its limits due to the rising number of satellites.

Demonstration of data transmission from a microsatellite by laser

This article originally appeared in <a href="https://news.itmo.ru/en/science/life_science/news/13440/" target="_blank" rel="noopener noreferrer">ITMO News</a> and has been republished with permission.<hr>A family of medical devices named implants are manufactured to replace a missing organ or its parts. Dental implants are implanted into the jaw to support replacement teeth. Apart from dentistry, implants are also used to resurface a knee, repair skull bones, as well as for other purposes.&nbsp;All medical devices are customized to each patient's unique characteristics. In the case of dental implants, doctors must be aware of a person's skull bones, gums, and roots to determine the appropriate form and size of the future implant.&nbsp;To make an implant last longer, as well as heal faster and easier, its surface is enhanced with functional features, like antibacterial properties and biocompatibility. The latter is usually accomplished by roughening up the implant's surface with sandblasting, followed by acid and anodizing to make the surface antimicrobial. So far, there is no one-stop complex to execute both procedures – except for the one currently under development at ITMO University.<img src="https://images.wevolver.com/eyJidWNrZXQiOiJ3ZXZvbHZlci1wcm9qZWN0LWltYWdlcyIsImtleSI6ImZyb2FsYS8xNjk3MTk5NTcwODA3LXAxMzQ0MC5qcGciLCJlZGl0cyI6eyJyZXNpemUiOnsid2lkdGgiOjk1MCwiZml0IjoiY292ZXIifX19" style="width: 766px;" class="fr-fic fr-dib">The research team (from left to right): Yulia Karlagina, Galina Romanova, Andrey Lisichnikov, and Fedor Inochkin. Photo courtesy of Evgeniy Shamshin<h2 dir="ltr" id="isPasted">The laser-based complex</h2>Researchers from ITMO’s Institute of Laser Technologies and their colleagues from Laser Center designed a multiuse robotic complex for surface treatment of diverse medical materials. According to the developers, the technology is equipped with a fiber laser system and possesses several advantages:&nbsp;Versatility. The technology is well-suited for use with medical devices such as scalpels and surgical scissors, as well as a variety of implants, including teeth, skull, hip, and knee replacements.&nbsp;Turnkey treatment in one system. The team created and merged several laser treatment options that are used consecutively:<ul><li dir="ltr">The technology for antibacterial surface properties prevents bacterial complications, which lead to implant rejection. Laser heating makes oxide layers grow on the surface of a titanium implant, which demonstrates bactericidal properties when exposed to a UV source.</li><li dir="ltr">The technology for biocompatible surface property. The laser is applied to generate a relief with unique properties on the surface, followed by the laser ablation process, which creates a biomimetic micro- and nanorelief that promotes excellent adhesion of proteins in the early stages of osseointegration, cell proliferation, and differentiation, ensuring implant success.&nbsp;</li><li dir="ltr">The technology for applying non-toxic identification labels on medical devices. Legally binding product labeling makes it possible to track the life cycle of a product, from its early production to the end user.&nbsp;</li></ul><blockquote>“We came up with a versatile device that makes it possible to functionalize a wide spectrum of medical equipment without any additional consumables or tools. The single system can boast several treatment options, related to the biocompatible and antibacterial properties of products, their roughness, as well as labeling,” states&nbsp;Yulia Karlagina, a junior researcher at ITMO’s Institute of Laser Technologies.</blockquote><img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1697199551134-ezgif-2-348e4b0195.gif" style="width: 766px;" class="fr-fic fr-dib">The robot laser complex in action. Video courtesy of Evgeniy ShamshinCompatibility with custom devices. All it takes is to load a 3D model of the implant into the program and indicate which elements of the 3D electronic geometric model need to be processed. The software was developed by the team at ITMO.&nbsp;The complex consists of a six-axis robotic manipulator and a laser scanning system mounted on the robot's arm, which ensures high accuracy of laser positioning, achieved by optical methods, and universality of robotic systems. Its ability to focus a laser beam on a product’s surface in all six spatial coordinates makes it possible to process products of complex shapes in one technological cycle.The team incorporated a computer vision system to make it easier for the operator to determine the position of the product in reality. In addition to its position, the system reports on its orientation and geometrical parameters to ensure precision laser processing.<blockquote>“The existing robotic solutions are aimed at mass-production items. Once adjusted for a specific device, they perform a series of programmed actions again and again. This approach is not suitable for small-scale or one-of-a-kind equipment, whereas our technology can be easily customized for a new product,” explains&nbsp;Fedor Inochkin, a researcher at ITMO’s Institute of Laser Technologies<img data-fr-image-pasted="true" alt="" src="https://news.itmo.ru/en/science/life_science/news/13440/" class="fr-fic fr-dii"></blockquote><img src="https://images.wevolver.com/eyJidWNrZXQiOiJ3ZXZvbHZlci1wcm9qZWN0LWltYWdlcyIsImtleSI6ImZyb2FsYS8xNjk3MTk5Mzg4MjEyLTEzNDQwMDEuanBnIiwiZWRpdHMiOnsicmVzaXplIjp7IndpZHRoIjo5NTAsImZpdCI6ImNvdmVyIn19fQ==" style="width: 766px;" class="fr-fic fr-dib">An operator positions a medical device and loads a 3D model into the system, selects the areas to be processed, and starts the program. The robot manipulator travels from one area to another with a laser beam. The procedure time varies depending on the chosen technology and item size. Photo courtesy of Evgeniy ShamshinA compact automated laser system for dental implants and their components is another device created by the team to serve exclusively dental purposes.&nbsp;<blockquote>“The systems have different functions, which affects their price and audience. If a customer needs to process a certain implant, like a dental one, they should purchase the second device, whereas the first one will be more beneficial with a wide range of items, including custom ones. For instance, a person who suffered from head injury can receive an individually designed skull implant. The multiuse system allows specialists to incorporate a desired set of properties into personalized implants in accordance to their unique shape,” notes Yulia Karlagina.&nbsp;</blockquote><img src="https://images.wevolver.com/eyJidWNrZXQiOiJ3ZXZvbHZlci1wcm9qZWN0LWltYWdlcyIsImtleSI6ImZyb2FsYS8xNjk3MTk5NDEwOTc4LTEzNDQwMDIuanBnIiwiZWRpdHMiOnsicmVzaXplIjp7IndpZHRoIjo5NTAsImZpdCI6ImNvdmVyIn19fQ==" style="width: 766px;" class="fr-fic fr-dib">An operator positions an implant, closes the complex’s cover, chooses the type of device under study and processing mode in the program, and, finally, starts the program. The implant is ready in 10-15 minutes. Photo courtesy of Evgeniy Shamshin<h2 dir="ltr" id="isPasted">Prospects of the technology</h2>The ITMO researchers in collaboration with their co-authors from Samara State University have carried out preliminary testing of both complexes, in particular preclinical trials of the processed medical devices. All samples were successfully tested in vitro and in vivo and are recommended for clinical trials.&nbsp;In the future, the developers plan to run acceptance tests to ensure the complexes are ready for operation and mass production. The team also intends to attract new industrial partners. In the long run, the systems are expected to be used in the production of medical equipment and implants.&nbsp;<blockquote>“We already have surface functionalization technologies for implants and soon we, with our colleagues from Laser Center, will start to look for new partners who will integrate them into their productions. If requested, we can also modify our products to the client’s needs – for instance, we can add a second robot manipulator that will upload new implants into the system instead of an operator,” notes Galina Romanova, a senior researcher at ITMO’s Institute of Laser Technologies.&nbsp;</blockquote><img src="https://images.wevolver.com/eyJidWNrZXQiOiJ3ZXZvbHZlci1wcm9qZWN0LWltYWdlcyIsImtleSI6ImZyb2FsYS8xNjk3MTk5NDQxMTQzLTEzNDQwMDMuanBnIiwiZWRpdHMiOnsicmVzaXplIjp7IndpZHRoIjo5NTAsImZpdCI6ImNvdmVyIn19fQ==" style="width: 766px;" class="fr-fic fr-dib">Galina Romanova. Photo courtesy of Evgeniy ShamshinThe project is implemented as part of the Government Decree No. 218 on request by Laser Center. Additionally, the developers continue to run research within ITMO’s 2030 Development Strategy.&nbsp;The research team has been working on the processing of medical titanium alloys for several years now. Together with their partners from Lenmiriot, they <a href="https://news.itmo.ru/en/science/new_materials/news/9655/" target="_blank">developed</a> a design of an implant surface that helps implants heal faster without inflammation. In 2022, Lenmiriot <a href="https://news.itmo.ru/en/startups_and_business/partnership/news/12313/" target="_blank">announced</a> the market launch of the dental implants made with the new laser technology.

The robot laser complex. Photo courtesy of Evgeniy Shamshin

Researchers from ITMO University have created a multipurpose robot complex for laser treatment of medical device surfaces, like those of dental and skull implants. The designed technology can be utilized to imbue metal implants with antibacterial and biocompatible properties, as well as mark medical items. All one needs to do is load a 3D model of an implant into a program, set a processing trajectory, and pick a surface attribute of choice.

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