Quantum simulators (or computers) are a promising means of solving complex computational tasks such as the encryption of data with quantum cryptography. Compared to conventional computers, quantum ones rely not on bits (which can have two states: 1 and 0), but on qubits (which can have many states). It is thanks to this property that quantum computers are expected to be capable of processing all states simultaneously, thus producing solutions faster than regular PCs.One major challenge on the way towards quantum computers is spontaneous emission – the possibility of a qubit being destroyed at any moment by emitting into its environment. This phenomenon shortens the life of quantum states and essentially renders the recording of information impossible in quantum systems. Large atomic structures (containing dozens or hundreds of atoms) are typically used to suppress spontaneous emission. Earlier, scientists from ITMO had <a href="https://www.degruyter.com/document/doi/10.1515/nanoph-2023-0624/html" target="_blank">discovered</a> 2D atomic arrays that can support quantum states of maximal longevity; however, the optimal design of structures with randomly located particles remained unknown.This time, through an optimization of geometry, the physicists were able to acquire structures that can support the quantum states longer by dozens and hundreds of times. For this, they used evolutionary algorithms (AI algorithms that model natural selection processes) to create a program that can predict the appropriate system parameters. Compared to other solutions, in which the atomic structures had predefined geometries, in this one the AI was responsible for identifying the correct atom locations.The suggested solution determines the geometry of molecules made up from ultracold atoms. In a sense, the team has provided a manual for assembling long-lived quantum systems for information recording and storage: the structures predicted by the AI can be used to develop quantum memory algorithms.<img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1713998613704-1369102.jpg" style="width: 100%px;" class="fr-fic fr-dib">A schematic of the algorithm that determines the optimal design of long-lived quantum structures. Image courtesy of the authorsIn their work, the authors considered two variables: the number of atoms and the minimal space between them. Using the algorithm, they determined the optimal geometry for different interatomic distances: 1D chains and fragments of square and triangle arrays. All of these configurations can support non-radiative – long-lived – quantum states.<blockquote>“There are two paths by which this project may continue. Until now, we have calculated the parameters for single-photon structures; next, we will look for the same things for two-photon tangled states: they can contain twice as much information, as well as be used in quantum communications for information transfer. Moreover, we’d like to improve our algorithm by enabling it to compute systems with a greater number of atoms,” shares&nbsp;Ilya Volkov, one of the paper’s authors and a PhD student at ITMO’s <a href="https://en.itmo.ru/en/faculty/106/fiziko-tehnicheskiy_megafakultet.htm" target="_blank">School of Physics and Engineering</a>.</blockquote>Thanks to this solution, the researchers will be able to extend the recording time of quantum states, thus opening up new possibilities for their application, including the development of quantum computers.<hr><a href="https://pubs.aip.org/aip/apl/article-abstract/124/8/084001/3266785/Non-radiative-configurations-of-a-few-quantum?redirectedFrom=fulltext" target="_blank">Reference</a>: Ilya Volkov, Stanislav Mitsai, Stepan Zhogolev, Danil Kornovan, Alexandra Sheremet, Roman Savelev, Mihail Petrov. Non-radiative configurations of a few quantum emitters ensembles: Evolutionary optimization approach (Applied Physics Letters, 2024)&nbsp;

Physicists from ITMO University have created an AI-based solution to make quantum states remain stable for longer for the processing, reliable recording, and storage of information. This study, described in a recent article in Applied Physics Letters, may help pave the way to quantum computers.

Longer-Lived Quantum States Suggested at ITMO

Researchers at the Georgia Institute of Technology have developed a light-based means of printing nano-sized metal structures that is significantly faster and cheaper than any technology currently available. It is a scalable solution that could transform a scientific field long reliant on technologies that are prohibitively expensive and slow. The breakthrough has the potential to bring new technologies out of labs and into the world.Technological advances in many fields rely on the ability to print metallic structures that are nano-sized — a scale hundreds of times smaller than the width of a human hair. <a href="https://www.me.gatech.edu/faculty/saha" target="_blank">Sourabh Saha</a>, assistant professor in the <a href="https://www.me.gatech.edu/" target="_blank">George W. Woodruff School of Mechanical Engineering</a>, and Jungho Choi, a Ph.D. student in Saha’s lab, developed a technique for printing metal nanostructures that is 480 times faster and 35 times cheaper than the current conventional method.Their research was <a href="https://onlinelibrary.wiley.com/doi/10.1002/adma.202308112" target="_blank">published</a> in the journal Advanced Materials.Printing metal on the nanoscale — a technique known as nanopatterning — allows for the creation of unique structures with interesting functions. It is crucial for the development of many technologies, including electronic devices, solar energy conversion, sensors, and other systems.It is generally believed that high-intensity light sources are required for nanoscale printing. But this type of tool, known as a femtosecond laser, can cost up to half a million dollars and is too expensive for most research labs and small businesses.“As a scientific community, we don’t have the ability to make enough of these nanomaterials quickly and affordably, and that is why promising technologies often stay limited to the lab and don’t get translated into real-world applications,” Saha said.“The question we wanted to answer is, ‘Do we really need a high-intensity femtosecond laser to print on the nanoscale?’ Our hypothesis was that we don’t need that light source to get the type of printing we want.”They searched for a low-cost, low-intensity light that could be focused in a way similar to femtosecond lasers, and chose superluminescent light emitting diodes (SLEDs) for their commercial availability. SLEDs emit light that is a billion times less intense than that of femtosecond lasers.Saha and Choi set out to create an original projection-style printing technology, designing a system that converts digital images into optical images and displays them on a glass surface. The system operates like digital projectors but produces images that are more sharply focused. They leveraged the unique properties of the superluminescent light to generate sharply focused images with minimal defects.They then developed a clear ink solution made up of metal salt and added other chemicals to make sure the liquid could absorb light. When light from their projection system hit the solution, it caused a chemical reaction that converted the salt solution into metal. The metal nanoparticles stuck to the surface of the glass, and the agglomeration of the metal particles creates the nanostructures. Because it is a projection type of printing, it can print an entire structure in one go, rather than point by point — making it much faster.After testing the technique, they found that projection-style nanoscale printing is possible even with low-intensity light, but only if the images are sharply focused. Saha and Choi believe that researchers can readily replicate their work using commercially available hardware. Unlike a pricey femtosecond laser, the type of SLED that Saha and Choi used in their printer costs about $3,000.“At present, only top universities have access to these expensive technologies, and even then, they are located in shared facilities and are not always available,” Choi said. “We want to democratize the capability of nanoscale 3D printing, and we hope our research opens the door for greater access to this type of process at a low cost.”The researchers say their technique will be particularly useful for people working in the fields of electronics, optics, and plasmonics, which all require a variety of complex metallic nanostructures.“I think the metrics of cost and speed have been greatly undervalued in the scientific community that works on fabrication and manufacturing of tiny structures,” Saha said.“In the real world, these metrics are important when it comes to translating discoveries from the lab to industry. Only when we have manufacturing techniques that take these metrics into account will we be able to fully leverage nanotechnology for societal benefit.”<hr>Citation: J. Choi, S. K. Saha, Scalable Printing of Metal Nanostructures through Superluminescent Light Projection. Adv. Mater. 2024, 36, 2308112.DOI: https://doi.org/10.1002/adma.202308112

The researchers developed a light-based means of printing nano-sized metal structures that is 480 times faster and 35 times cheaper than the current conventional method.

Researchers Create Faster and Cheaper Way to Print Tiny Metal Structures With Light

Lights could soon use the full color suite of perfectly efficient organic light-emitting diodes, or OLEDs, that last tens of thousands of hours, thanks to an innovation from physicists and engineers at the University of Michigan.The U-M team’s new phosphorescent OLEDs, commonly referred to as PHOLEDs, can maintain 90% of the blue light intensity for 10-14 times longer than other designs that emit similar deep blue colors. That kind of lifespan could finally make blue PHOLEDs hardy enough to be commercially viable in lights that meet the Department of Energy’s 50,000-hour lifetime target. Without a stable blue PHOLED, OLED lights need to use less-efficient technology to create white light.The lifetime of the new blue PHOLEDs currently is only long enough to use as lighting, but the same design principle could be combined with other light-emitting materials to create blue PHOLEDs hardy enough for TVs, phone screens and computer monitors. Display screens with blue PHOLEDs could potentially increase a device’s battery life by 30%.“Achieving long-lived blue PHOLEDs has been a focus of the display and lighting industries for over 20 years. It is probably the most important and urgent challenge facing the field of organic electronics,” said <a href="https://eecs.engin.umich.edu/people/forrest-stephen-r/" target="_blank" rel="noreferrer noopener">Stephen Forrest</a>, the Peter A. Franken Distinguished University Professor of Electrical and Computer Engineering at the University of Michigan. He is also the corresponding author of the study published today in Nature.<img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1703720458568-Haonan-and-Claire-lab-1-1.jpg" style="width: 300px;" class="fr-fic fr-dib">Haonan Zhao and Claire Arneson, two doctoral students in physics and graduate student research assistants in electrical and computer engineering at the University of Michigan, fabricate their blue PHOLED devices in the lab. Their design prevents the excited molecules within the PHOLEDs light-emitting material from colliding, which could break the bonds holding the molecules together. Photo credit: Miranda Felty, University of MichiganPHOLEDs have nearly 100% internal quantum efficiency, meaning all of the electricity entering the device is used to create light. As a result, lights and display screens equipped with PHOLEDs can run brighter colors for longer periods of time with less power and carbon emissions.Before the U-M team’s research, the best blue PHOLEDs weren’t durable enough to be used in either lighting or displays. Only red and green PHOLEDs are stable enough to use in devices today, but blue is needed to complete the trio of colors in OLED “RGB” displays and white OLED lights. Red, green and blue light can be combined at different relative brightness to produce any color desired in display pixels and light panels.So far, the workaround in OLED displays has been to use older, fluorescent OLEDs to produce the blue colors, but the internal quantum efficiency of that technology is much lower. <a href="https://pubs.rsc.org/en/content/articlehtml/2023/tc/d3tc00245d" target="_blank" rel="noreferrer noopener">Only a quarter</a> of the electric current entering the fluorescent blue device produces light.“A lot of the display industry’s solutions are upgrades to fluorescent OLEDs, which is still an alternative solution,” said study first author Haonan Zhao, a doctoral student in physics and electrical and computer engineering. “I think a lot of companies would prefer to use blue PHOLEDs, if they had the choice.”To make blue light, electricity excites heavy metal-containing phosphorescent organic molecules. Sometimes, the excited molecules come into contact before emitting the light, transferring all of the pair’s stored energy into one molecule. Because the energy of blue light is so high, the transferred energy, which is double that of the single excited molecule, can break chemical bonds and degrade the organic material.One way around this problem is to use materials that emit a broader spectrum of colors, which lowers the total amount of energy in the excited states. But such materials appear cyan or even green, rather than a deep blue.The U-M team got around this issue by sandwiching cyan material between two mirrors. By perfectly tuning the space between the mirrors, only the deepest blue light waves can persist and eventually emit from the mirror chamber.Further tuning the optical properties of the organic, light-emitting layer to an adjacent metal electrode introduced a new quantum mechanical state called a plasmon-exciton-polariton, or PEP. This new state allows the organic material to emit light very fast, thus further decreasing the opportunity for excited states to collide and destroy the light-emitting material.&nbsp;<img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1703720495886-Haonan-and-Claire-lab-2-1.jpg" style="width: 300px;" class="fr-fic fr-dib">The research team constructs their blue PHOLEDs inside a glovebox that keeps the PHOLEDs away from oxygen and water before they are fully encased in nitrogen. It’s a standard procedure that protects the device’s sensitive optics and electronics. Photo credit: Miranda Felty, University of Michigan“In our device, the PEP is introduced because the excited states in the electron transporting material are synchronized with the light waves and the electron vibrations in the metal cathode,” said study co-author Claire Arneson, a doctoral student in physics and electrical and computer engineering.

Lights could soon use the full color suite of perfectly efficient organic light-emitting diodes, or OLEDs, that last tens of thousands of hours, thanks to an innovation from physicists and engineers at the University of Michigan.

Blue PHOLEDs: Final color of efficient OLEDs finally viable in lighting

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

Exploring Silicon Photonics: Shaping the Future of Optical Communication

Silicon Photonics: A Comprehensive Guide to the Future of Optical Communications

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

Integrated photonics, also known as planar lightwave circuits or integrated optical circuits, revolutionizes optical communication by leveraging the properties of light to process and transmit information. This cutting-edge technology offers superior efficiency and compactness compared to traditional electronic components, paving the way for faster and more energy-efficient communication systems. With its interdisciplinary nature encompassing materials science, quantum physics, and electrical engineering, integrated photonics presents an exciting and promising field of study and research in today's digital era.


Integrated Photonics: Comprehensive Guide to Optical Communication

This article was first published on&nbsp;<a href="https://news.mit.edu/2023/study-reveals-new-ways-exotic-quasiparticles-relax-0512" id="isPasted" rel="noopener noreferrer" target="_blank">MIT News</a>. &nbsp;<hr>New findings from a team of researchers at MIT and elsewhere could help pave the way for new kinds of devices that efficiently bridge the gap between matter and light. These might include computer chips that eliminate inefficiencies inherent in today&rsquo;s versions, and qubits, the basic building blocks for quantum computers, that could operate at room temperature instead of the ultracold conditions needed by most such devices.The new work, based on sandwiching tiny flakes of a material called perovskite in between two precisely spaced reflective surfaces, is detailed in the journal&nbsp;Nature Communications, in a&nbsp;<a href="https://www.nature.com/articles/s41467-023-37772-7" target="_blank">paper</a> by MIT recent graduate Madeleine Laitz PhD &rsquo;22, postdoc Dane deQuilettes, MIT professors Vladimir Bulovic, Moungi Bawendi and Keith Nelson, and seven others.By creating these perovskite sandwiches and stimulating them with laser beams, the researchers were able to directly control the momentum of certain &ldquo;quasiparticles&rdquo; within the system. Known as exciton-polariton pairs, these quasiparticles are hybrids of light and matter. Being able to control this property could ultimately make it possible to read and write data to devices based on this phenomenon.&ldquo;What&rsquo;s particularly fascinating about exciton-polaritons,&rdquo; Laitz says, is that they lie &ldquo;on a spectrum between purely electronic and photonic systems.&rdquo; These quasiparticles &ldquo;have the characteristics of both, and thus you can leverage exciton-polaritons to utilize the best properties of each.&rdquo;For example, purely electronic transistors, she explains, have inherent losses to capacitance effects at each interface between devices, whereas &ldquo;purely photonic systems have challenges in engineering, in that it&rsquo;s very hard to get photons to interact, and you have to rely on complex interferometric schemes.&rdquo; By contrast, the quasiparticles used by this team can be easily controlled through multiple variables.The quasiparticle is &ldquo;a combined state of light and neutral charge,&rdquo; Bulovic says. &ldquo;As a result, you can perturb that combined state either with light or charge, and hence, if you need to modulate that state, you have extra levers you can utilize. These extra levers can now allow one to manipulate this combined state of matter in a more energy-efficient manner.&rdquo;What&rsquo;s more, the materials involved are easily manufactured using room-temperature, solution-based processing methods, and thus could be relatively easy to produce at scale once practical systems are designed. So far, the work is at a very early stage, as researchers are still studying newly discovered effects; practical applications could be five to 10 years away, Laitz says.Perovskites have attracted much attention in recent years as materials for new lightweight, flexible solar photovoltaic panels, so there has been a great deal of research on their properties and fabrication methods. The team settled on a particular version of perovskite called phenethylammonium lead iodide.&ldquo;Halide perovskites harvest light really well, and turn photons into electrons or excitons, depending on the dimensionality and material properties of the perovskite,&rdquo; she says, which is why the researchers chose this particular version of this large class of materials for their research.Then, to create what is known as an optical cavity that can trap photons of light, the researchers placed tiny flakes of the material between mirrored surfaces. Two of these ultrathin layers, just tens of nanometers thick, were spaced a precise distance apart using spacer layers, so that the mirrors were separated by half the wavelength of light that this perovskite material both absorbs and emits.Using perovskite tuned to a wavelength of green light, the emitted green light then bounces back and forth between the mirrors. &ldquo;It&rsquo;s reabsorbed by the material, re-emitted, reabsorbed, re-emitted, reabsorbed over and over again so quickly that you&rsquo;re interconverting between the photon and the exciton, such that you generate a superposition of both,&rdquo; Laitz says.This can lead to the state of matter known as a Bose-Einstein Condensate, in which all the particles have identical energy states and behave much like one large particle. Laitz says that such condensates carry a property known as spin, and this can be modified by light or electrical stimulation; the resulting changes can be measured by observing photoluminescence from the material using a spectroscopic imaging system. And unlike purely photonic systems, where there is little interaction between photons, these materials have strong interactions with both light and electrons.Arrays of such condensates have been produced, but typically only at ultralow, cryogenic temperatures so far. &ldquo;Perovskites offer the opportunity for realizing this phenomenon at elevated temperatures,&rdquo; but it&rsquo;s hard to form the condensates in perovskites. This new research shows fundamental characteristics of the process that leads to condensation, Laitz says. In their paper, &ldquo;we propose several strategies from a material perspective and a device architecture perspective to enable this.&rdquo; And that could be a key step toward eventual room-temperature qubits, she says.While such devices may take several years to develop, a more near-term application of the new findings could be in producing new kinds of light-emitting devices, deQuilettes says, including ones that could provide a steerable light source with directional output that can be controlled electronically.&ldquo;There has been quite a bit of interest in using exciton-polaritons as the basis for low-power coherent light sources, similar to lasers,&rdquo; says St&eacute;phane K&eacute;na-Cohen an associate professor of engineering physics at the Montreal Polytechnic, who was not associated with this work.&nbsp;&ldquo;In that area, the challenge is to get polaritons to relax efficiently to their lowest energy state. This paper helps us understand the details of how this happens in perovskite microcavities, and how to better design cavities to make this happen at very low power.&rdquo;The research team also included Alexander Kaplan, Jude Deschamps, Ulugbek Barotov, Andrew Proppe, and Anna Asherov at MIT, Ines Garcia-Benito at Complutense University of Madrid, and Giulia Grancini at the University of Pavia. The work was supported by the Tata-MIT GridEdge Solar Research Program, the National Science Foundation, and the European Research Council.<hr>&quot;Reprinted with permission of&nbsp;<a href="https://news.mit.edu/2023/study-reveals-new-ways-exotic-quasiparticles-relax-0512" id="isPasted" rel="noopener noreferrer" target="_blank">MIT News</a>&quot; &nbsp;

By sandwiching bits of perovskite between two mirrors and stimulating them with laser beams, researchers were able to directly control the spin state of quasiparticles known as exciton-polariton pairs, which are hybrids of light and matter. Image: Courtesy of the researchers

A perovskite-based device that combines aspects of electronics and photonics may open doors to new kinds of computer chips or quantum qubits.

Study reveals new ways for exotic quasiparticles to "relax"

Photonic time crystals, whose properties change periodically, promise significant advances in microwave technology, optics and photonics. Researchers at the Karlsruhe Institute of Technology (KIT), together with partners at Aalto University and Stanford University, have now produced a two-dimensional photonic time crystal for the first time and demonstrated important applications. Their approach simplifies the production of photonic time crystals and can improve the efficiency of future communication systems.In the broadest sense, time crystals belong to the so-called metamaterials, which are artificially produced and have properties that do not occur in nature.&nbsp;In 2012, the physics Nobel Prize winner Frank Wilczek presented the fascinating concept of time crystals for the first time.&nbsp;Unlike ordinary crystals, time crystals do not change their properties in space, but periodically in time.&nbsp;Photonics researchers are currently working on the first optical versions of these materials, known as photonic time crystals.&nbsp;These crystals have great potential for improving wireless communication signals and may enable a new generation of lasers in the future, as light propagating in photonic time crystals can be effectively amplified.<h2>Reduction of dimensionality facilitates realization</h2>So far, research in the field of photonic time crystals has focused on bulk materials, i.e. three-dimensional structures.&nbsp;However, the realization of photonic time crystals in such materials represents an enormous challenge and the experiments have so far not gone beyond model systems.&nbsp;Practical applications of these three-dimensional structures have not yet come about.&nbsp;Researchers from the Institute of Nanotechnology and the Institute for Theoretical Solid State Physics (TFP) of KIT, together with partners from Aalto University in Finland and Stanford University in the USA, have now developed a new approach and presented it in the journal Science Advances: The team has one for the first time two-dimensional photonic time crystal.&nbsp;It is a very thin layer of such metamaterial.&nbsp;&ldquo;We have found that reducing the dimensionality from a 3D to a 2D structure greatly simplifies implementation.&nbsp;This made it possible to realize photonic time crystals,&quot; explains Dr.&nbsp;Xuchen Wang, the main author of the study, who is currently conducting research at KIT in the group of Professor Carsten Rockstuhl at the TFP.&nbsp;The team designed and synthesized a two-dimensional electromagnetic structure.&nbsp;This contains tunable components periodically embedded in time that change their electromagnetic properties.&nbsp;By using this structure, it was possible to experimentally confirm the theoretically predicted behavior.<h2>Photonic time crystals in 2D make communication more efficient</h2>The pioneering development enables advances in various technologies, such as wireless communication, integrated circuits and lasers.&nbsp;By amplifying electromagnetic waves, wireless transmitters and receivers can become more powerful and efficient in the future.&nbsp;In addition, coating surfaces with two-dimensional photonic time crystals can reduce signal dropout in wireless transmission.&nbsp;This often represents a bottleneck. The use of two-dimensional photonic time crystals can also simplify the construction of lasers in the future, since complex mirror systems, such as those normally used in laser resonators, are no longer required.Another important application arises from the realization that photonic time crystals in 2D amplify not only the incoming free-space electromagnetic waves, but also surface waves, which are used for communication between electronic components in integrated circuits. Surface waves suffer from absorption losses in the material, reducing signal strength. &quot;By using two-dimensional photonic time crystals covering the propagation medium, the surface acoustic wave can be amplified, which improves communication efficiency,&quot; says Wang.&nbsp;<hr><h3>Original publication</h3>Xuchen Wang, Mohammad Sajjad Mirmoosa, Viktar S Asadchy, Carsten Rockstuhl, Shanhui Fan, &amp; Sergei A Tretyakov: Metasurface-Based Realization of Photonic Time Crystals. Science Advances, 2023. DOI: 10.1126/sciadv.adg7541

A 2D photonic time crystal can amplify free space and surface waves. (Graphic: Dr. Xuchen Wang, KIT)

Photonic time crystals, whose properties change periodically, promise significant advances in microwave technology, optics and photonics. Researchers at the Karlsruhe Institute of Technology (KIT), together with partners at Aalto University and Stanford University, have now produced a two-dimensional photonic time crystal for the first time and demonstrated important applications.

Metamaterials: Time Crystal Gets Light Going

We proclaim 2022 The Year of Innovation. In this &quot;End of the Year&quot; list we highlight 25 Campus high-tech, innovative companies, including multi-nationals, startups, scale-ups and everything in-between. These are companies of the future, and they&rsquo;re all here at HTCE.Disclaimer: With 280+ inspiring companies on Campus, a &quot;End of the Year&quot; list is never complete. These 25 companies participated&nbsp;<a href="https://www.youtube.com/watch?v=xAJJeJZ8hNI&ab_channel=HighTechCampusEindhoven" rel="noopener" target="_blank">High Tech Next</a>, our conference of the year, showcasing their latest technologies.&nbsp;<h2>Healthcare</h2>STENTiT <a href="https://www.stentit.com/" rel="noopener" target="_blank">STENTiT</a> makes an endovascular stint that includes a regenerative element that helps actually heal the artery. STENTiT CEO Bart Sanders said his startup&rsquo;s technology, developed at the Eindhoven University of Technology, is unique in that &ndash; in addition to opening the clogged passageways &ndash; has regenerative qualities that are unique, healing the artery without invasive surgery.<img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1677503675561-Ontwerp+zonder+titel-Jan-02-2023-11-25-33-8556-AM.png" style="width: 766px;" class="fr-fic fr-dib">Teledyne DALSA <a href="https://www.teledynedalsa.com/en/home/" rel="noopener" target="_blank">Teledyne DALSA</a> is a&nbsp;global company&nbsp;designing and manufacturing specialized electronic imaging components as well as specialized semiconductor fabrication. The company develops and produces sensors and detectors for digital imaging that are used in a wide variety of applications.&nbsp;Its imaging sensors, digital cameras and image processing software are used for everything from aerial photogrammetry to medical radiography.Sirius Medical <a href="https://www.sirius-medical.com/" rel="noopener" target="_blank">Sirius Medical</a> has technology that provides real-time, directional guidance using audio and visual feedback for increased precision in locating tumors, said Marketing Manager Benjamin Tchang. Sirius&rsquo;&nbsp;Pintuition Seed is a tiny permanent magnetic seed that marks the tumor and helps with surgical removal from any direction.Philips Founded in Eindhoven in 1891, <a href="https://www.philips.nl/" rel="noopener" target="_blank">Philips</a> created some of the most popular consumer products&nbsp;in history,&nbsp;from cassette tapes and CDs to plasma TVs,&nbsp;at what is now High Tech Campus Eindhoven.&nbsp;Today, Philips has transformed into a global leader in health technology, improving health and well-being through meaningful innovation. Thousands of employees and more than one hundred years in operation, they still have one enduring belief: there&rsquo;s always a way to make life better. And they do that every day from the same R&amp;D location they started from, High Tech Campus Eindhoven.Faulhaber <a href="https://www.faulhaber.com/" rel="noopener" target="_blank">Faulhaber</a> is an innovator in miniature and micro drive systems. They design and manufacture drive solutions for numerous sectors, such as robotics, aerospace, medicine and lab technology. The BeBionic hand allows quick, precise and firm grip for people with handicaps to perform everyday tasks with much greater ease. The Gowing arm support system aids those with reduced arm strength, allowing them more freedom of movement.&nbsp;<img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1677503700788-Ontwerp+zonder+titel-Jan-02-2023-11-26-42-3767-AM.png" style="width: 766px;" class="fr-fic fr-dib">Sparckel <a href="https://sparckel.com/" rel="noopener" target="_blank">Sparckel</a> makes a new lamp that provides more than light. In collaboration with Philips, TU/e and other entities, Sparckel technology fights the decrease in daylight we experience indoors in the office, and at home in the winter. The lighting products improve mood and attention span by harnessing the power of natural sunlight.<h2>Emerging (Digital) Tech</h2>Flying Forward 2020 Flying Forward 2020 is not a tech company per se, but it is an ecosystem builder. FF2020 is developing and testing drones as part of a new Urban Air Mobility ecosystem which will put autonomous drones to work in urban environments. Fun fact: High Tech Campus Eindhoven serves as Flying Forward&rsquo;s first living lab for testing autonomous drones. The three-year research and development project is funded by the European Union.<img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1677503731054-Ontwerp+zonder+titel-Jan-02-2023-11-27-26-3796-AM.png" style="width: 766px;" class="fr-fic fr-dib">Datacation <a href="https://www.datacation.nl/" rel="noopener" target="_blank">Datacation</a> is a startup consulting firm working on applying machine learning and artificial intelligence to clients&rsquo; businesses to make them more efficient. Projects include developing an app to detect pancreatic cancer at an earlier stage and in a more accurate way using computer vision on CT Scans. Other projects include generating the essential text data from millions of emails, building recommendation systems for food delivery platforms and fan shops, advising on a data strategy plan and visualizing data in dashboards for multiple applications.Axelera AI <a href="https://www.axelera.ai/" rel="noopener" target="_blank">Axelera AI</a> is developing hardware/software solutions for AI inference at the Edge, enabling computer vision applications to become more accessible, powerful and user friendly. Axelera&rsquo;s AI inference technology can &ldquo;learn,&rdquo; in the sense it can adjust outcomes using new data. Axelera is unique in that it is both a software and hardware company, announcing the release of its MetisAI Platform,&nbsp;encompassing the Metis AI Processing Unit chip and the Voyager SDK software stack, said Merlijn Linschooten, marketing and communications manager. Axelera has raised $27 million in capital as of late 2022.<img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1677503750625-Ontwerp+zonder+titel-Jan-02-2023-11-28-05-1495-AM.png" style="width: 766px;" class="fr-fic fr-dib">Enliven <a href="https://enliven.one/" rel="noopener" target="_blank">Enliven</a> is creating virtual reality technology to address issues such as abuse and&nbsp;addiction. The Enliven simulations are realistic even to the point that adults in the abuse simulations are how they would appear to a child, said founder Alex Tavassoli. Enliven is currently in the LUMO Labs venture building program on HTCE.chunkx Founded in 2018 by Florian Stieler,&nbsp;<a href="https://about.chunkx.io/en/" rel="noopener" target="_blank">chunkx</a> is an AI-enhanced microlearning application that creates a curated and personalized learning experience by selecting content adaptively. Chunkx had developed an adaptive learning app using algorithms and AI to create interactive, personalized micro-learning lessons. Their AI-based apps and services allow users to practice continuous micro-learning for more sustainable knowledge acquisition.<h2>Photonics</h2>PhotonFirst <a href="https://www.photonfirst.com/" rel="noopener" target="_blank">PhotonFirst</a>&#39;s slogan is, &ldquo;We measure the world.&rdquo; Their photonic sensors measure everything from aerospace fuel system temperature to carbon fiber shape changes, EV battery temperature, infrastructure strain measurement and acoustic monitoring in medical systems. Earlier this year, American conglomerate GE and PhotonFirst entered into a strategic technology collaboration to develop fiber optic sensing for the monitoring of next-generation electrical grid infrastructure.<img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1677503766297-Ontwerp+zonder+titel-Jan-02-2023-11-28-57-7574-AM.png" style="width: 766px;" class="fr-fic fr-dib">SMART Photonics <a href="https://smartphotonics.nl/" rel="noopener" target="_blank">SMART Photonics</a> is a foundry designing and making specialized integrated photonic chips for clients in healthcare, telecommunications and other industries.PhotonDelta <a href="https://www.photondelta.com/" rel="noopener" target="_blank">PhotonDelta</a> is a cross-border ecosystem of photonic chip technology organizations. Faster, lighter, more durable and, at the end of the day, much cheaper, the benefits of photonic circuits are considerable for a wide range of applications. And the Netherlands plays an important role globally in the development and application of this key technology. I In April 2022, PhotonDelta landed &euro;1.1 billion in public and private investment to transform the Netherlands into the leader of next generation semiconductors.<img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1677503783055-Ontwerp+zonder+titel-Jan-02-2023-11-29-39-8326-AM.png" style="width: 766px;" class="fr-fic fr-dib">Aircision <a href="https://www.aircision.com/" rel="noopener" target="_blank">Aircision</a> is a leader in developing ultra-high-capacity optical wireless communication solutions for mobile backhaul, mobile broadband and private networks. Aircision&rsquo;s most recent tests show higher data transmission links than any competitor, said CFO and co-founder Betsy Lindsey. Aircision has tested with some of the world&rsquo;s largest telecommunications companies, with the goal of providing the technology to provide digital communications to underserved populations. &ldquo;We were recently awarded TOP 5 Startup at the GSMA&rsquo;s 2023 Mobile World Congress, and Aircision will be competing in February in Barcelona at the 4YFN event,&rdquo; Lindsey said.<h2>Sustainability</h2>Workplace Vitality Hub <a href="https://workplacevitalityhub.nl/" rel="noopener" target="_blank">Workplace Vitality Hub</a> is a new living lab at HTCE. In this unique collaboration with business partners Fontys, imec, TNO, TU/e and Twice, they develop innovative and effective solutions for a vital working environment. Here they research and develop new technologies and applications focused on the needs of working people, striving to make them &ndash; and the buildings they work in &ndash; more vital.<img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1677503811187-Ontwerp+zonder+titel-Jan-02-2023-11-30-15-7940-AM.png" style="width: 766px;" class="fr-fic fr-dib">Solliance Solar Research <a href="https://www.solliance.eu/nl/home-nl/" rel="noopener" target="_blank">Solliance</a> is a network of tech talents developing thin-film solar technology. Solliance cells are much thinner and more flexible than conventional solar cells, giving them the ability to take on virtually any shape.&nbsp;inPhocal <a href="https://inphocal.com/" rel="noopener" target="_blank">inPhocal</a> uses proprietary laser technology for advanced industrial printing. Think nearly instant printing on curved surfaces including bottles and cans. inPhocal now has its first product, which they&rsquo;re shipping to clients for field testing, said Robert van Tankeren, CEO. inPhocal closed its seed round in September; had its first sales in November; expanded its team to 12 people from six and received a 2.5 million euro EIC subsidy in December. &ldquo;Our production is ready to roll out certified systems,&rdquo; he said.<img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1677503832326-Ontwerp+zonder+titel-Jan-02-2023-11-31-25-9584-AM.png" style="width: 766px;" class="fr-fic fr-dib">Demcon <a href="https://demcon.com/" rel="noopener" target="_blank">Demcon</a> develops smart applications for healthcare, safety, water, energy, production and communication, to name just a few. Demcon meets all the needs of their global customers, from initial idea and concept, to prototyping, industrialization and production. Demcon develops its own products as well and invests in startups and established companies through their innovation program, focusing on projects that have a positive impact on people and the environment.Signify <a href="https://www.signify.com/global" rel="noopener" target="_blank">Signify</a> is one of the Big Four global companies in Eindhoven along with ASML, NXP and VDL. Signify, formerly Philips Lighting, makes LED lighting for multiple industries, including agriculture, office interiors, manufacturing facilities and others. CEO Eric Rondolat said Signify has moved past Horizon One (older products) and Horizon Two (current technology) to Horizon Three, with the company spending heavily on future technologies. &ldquo;From the era of conventional (connectivity) to an era of LED connectivity and new technology in Horizon Three, innovation is a big part of our story,&rdquo; Rondolat said. Watch his keynote&nbsp;<a href="https://www.youtube.com/watch?v=xAJJeJZ8hNI&ab_channel=HighTechCampusEindhoven" rel="noopener" target="_blank">here</a>.&nbsp;Carbyon <a href="https://carbyon.com/" rel="noopener" target="_blank">Carbyon</a> has developed technology that removes CO2 from the atmosphere. This spinout from TNO received millions in funding during 2022, including $1 million from Elon Musk&rsquo;s XPRIZE carbon removal competition. &ldquo;We&rsquo;re finalizing our protype, which will debut at the beginning of 2023,&rdquo; said COO Marco Arts. &ldquo;At next year&rsquo;s High Tech Next, we&rsquo;ll be able to show it.&rdquo;<img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1677503847928-Ontwerp+zonder+titel-Jan-02-2023-11-31-25-9584-AM.png" style="width: 766px;" class="fr-fic fr-dib">ESTI (Ecosystem Thinking Institute) The&nbsp;<a href="https://www.esti.site/" rel="noopener" target="_blank">Ecosystem Thinking Institute</a> is a non-profit organization which combines the Open Innovation Academy and the House of Open Innovation. They start with a problem-driven approach and bring together organizations dealing with the same problem. ESTI does extensive research and develop a landscape of the entire ecosystem, using proven methods and tools to build, guide and measure ecosystems in smart living, sustainability and social equality. &nbsp;All under the inspiring leadership of Margot Nijkamp, one of the first Campus residents.<h2>Mobility</h2>TomTom <a href="https://www.tomtom.com/nl_nl/navigation/" rel="noopener" target="_blank">TomTom</a> specializes in navigation technology and is a pioneer in personal navigation. Now, TomTom executives are building the smartest, most useful map on the planet. TomTom developed technology that&rsquo;s the future of in-vehicle digital cockpits. Infotainment and driving assistance are delivered to the driver in a safe and rich platform, which can be easily customized to fit car brands. Their new mapping technology make certain guidance and assistance are visualized precisely and clearly.The 5G Hub The <a href="https://5ghub.nl/nl/" rel="noopener" target="_blank">5G Hub</a>&nbsp;at HTCE is a lab for developing the latest in 5G telecommunications technology in partnership with Ericsson and VodafoneZiggo. The 5G Hub partners and companies (including startups) focus on four &#39;&#39;futures,&rdquo; including the Future of Health, the Future of Industry, the Future of Entertainment and the Future of Talent. Hub residents use 5G technologies and infrastructure, where they have space, time, feedback and guidance to develop their innovative ideas into business applications.<img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1677503870216-Ontwerp+zonder+titel-Jan-02-2023-11-32-02-1470-AM.png" style="width: 766px;" class="fr-fic fr-dib">NXP <a href="https://www.nxp.com/" rel="noopener" target="_blank">NXP</a> is one of the world&rsquo;s dominant semiconductor companies, making specialized chips for several industries, most notably these days for embedded technology in the auto industry. NXP chips are also used in Apple iPhones and they&rsquo;re working with the American company to develop its electric car.&nbsp;

We proclaim 2022 The Year of Innovation. In this "End of the Year" list we highlight 25 Campus high-tech, innovative companies, including multi-nationals, startups, scale-ups and everything in-between. These are companies of the future, and they’re all here at HTCE.

25 high tech companies on Campus you should know about

<section id="isPasted">Solar panels with multiple stacked cells are currently breaking records. Remarkably, a team of researchers from Eindhoven University of Technology and TNO at Holst Centre have now managed to make photodiodes - based on a similar technology - with a photoelectron yield of more than 200 percent. You would think that efficiencies of more than 100 percent are only possible using alchemy and other Harry Potter-like wizardry. But it can be done. The answer lies in the magical world of quantum efficiency and stacked solar cells.</section><section tabindex="-1"><a href="https://www.tue.nl/en/research/researchers/rene-janssen/" target="_blank">Ren&eacute; Janssen</a>, professor at TU/e and co-author of a new Science Advances paper, explains. &ldquo;I know, this sound incredible. But, we&rsquo;re not talking about normal energy efficiency here. What counts in the world of photodiodes is quantum efficiency. Instead of the total amount of solar energy, it counts the number of photons that the diode converts into electrons. I always compare it to the days when we still had guilders and lira. If a tourist from the Netherlands received only 100 lira for their 100 guilders during their holiday in Italy, they might have felt a bit shortchanged. But because in quantum terms, every guilder counts as one lira, they still achieved an efficiency of 100 per cent. This also holds for photodiodes: the better the better the diode is able to detect weak light signals, the higher its efficiency.&rdquo;<h2>Dark current</h2>Photodiodes are light-sensitive semiconductor devices that produce a current when they absorb photons from a light source. They are used as sensors in a variety of applications, including medical purposes, wearable monitoring, light communication, surveillance systems, and machine vision. In all these domains, high sensitivity is key.&nbsp;For a photodiode to work correctly, it has to meet two conditions. Firstly, it should minimize the current that is generated in the absence of light, the so-called dark current. The less dark current, the more sensitive the diode. Secondly, it should be able to distinguish the level of background light (the &lsquo;noise&rsquo;) from the relevant infrared light. Unfortunately, these two things usually do not go together, on the contrary.<img src="https://images.wevolver.com/eyJidWNrZXQiOiJ3ZXZvbHZlci1wcm9qZWN0LWltYWdlcyIsImtleSI6ImZyb2FsYS8xNjc2ODkwOTEwMjgzLWNzbV9Cdk9GIDIwMjNfMDIxNF9BUEYgLSBwaG90b2Rpb2RlIHJlc2VhcmNoIGJ5IFJpY2NhcmRvIE9sbGVhcm9fM2U4NGY0YWU4NS5qcGciLCJlZGl0cyI6eyJyZXNpemUiOnsid2lkdGgiOjk1MCwiZml0IjoiY292ZXIifX19" style="width: 766px;" class="fr-fic fr-dib">The photodiode used in the experiment (Photo: Bart van Overbeeke)&nbsp;<h2 id="isPasted">Tandem</h2>Four years ago, <a href="https://research.tue.nl/en/persons/riccardo-ollearo" target="_blank">Riccardo Ollearo</a>, one of Janssen&rsquo;s PhD students and lead author of the paper, set about solving this conundrum. In his research he joined forces with the photodetector team working at <a href="https://holstcentre.com/" target="_blank">Holst Centre</a>, a research institute specialized in wireless and printed sensor technologies, Ollearo built a so-called tandem diode, a device that combines both perovskite and organic PV cells.Combining these two layers &ndash; a technique also increasingly used in state-of-the-art solar cells &ndash; he was able to optimize both conditions, reaching an efficiency of 70 per cent.&nbsp;&ldquo;Impressive, but not enough&rdquo;, says the ambitious young researcher from Italy. &ldquo;I decided to see if I could increase the efficiency even further with the help of green light. I knew from earlier research that Illuminating solar cells with additional light can modify their quantum efficiency, and in some cases enhance it. To my surprise, this worked even better than expected in improving the photodiode sensitivity. We were able to increase the efficiency for near-infrared light to over 200 per cent!&rdquo;<h2>Mystery</h2>Up this point, the researchers still don&rsquo;t know exactly how this works, although they&rsquo;ve come up with a theory that might explain the effect. &ldquo;We think that the additional green light leads to a build-up of electrons in the perovskite layer. This acts as a reservoir of charges that is released when infrared photons are absorbed in the organic layer&rdquo;, says Ollearo. &ldquo;In other words, every infrared photon that gets through and is converted in an electron, gets company from a bonus electron, leading to an efficiency of 200 per cent or more. Think of it as getting two lira for your guilder, instead of one!&rdquo;<img src="https://images.wevolver.com/eyJidWNrZXQiOiJ3ZXZvbHZlci1wcm9qZWN0LWltYWdlcyIsImtleSI6ImZyb2FsYS8xNjc2ODkwOTQ5ODk2LWNzbV9OZXdzIHRhbmRlbSBQUERfYWUyN2U4OGNjMC5wbmciLCJlZGl0cyI6eyJyZXNpemUiOnsid2lkdGgiOjk1MCwiZml0IjoiY292ZXIifX19" style="width: 766px;" class="fr-fic fr-dib">In the left image we see the set-up in which the new tandem photodiode can be used to monitor the heart and respiration rates of a person. The right images show the detected heart and respiration signals recorded with the photodiode at a distance of 130 cm.&nbsp;<section id="isPasted" tabindex="-1"><h2>Putting the diode to the test</h2>Ollearo tested the photodiode, which is hundred times as thin as a sheet of newsprint, and suitable for use in flexible devices,, in the lab. &ldquo;We wanted to see whether the device could pick up subtle signals, such as the heart or respiration rate of a human being in an environment with realistic background light. We opted for an indoor scenario, during a sunny day with the curtains partially closed. And it worked!&rdquo; Holding the device at 130 cm from a finger, the researchers were able to detect minute changes in the amount of infrared light that was reflected back into the diode. These changes turn out to be a correct indication of changes in the blood pressure in a person&rsquo;s veins, which in turn indicate heart rate. When pointing the device at the person&rsquo;s chest, they were able to measure the respiration rate from light movements in the thorax (see image)&rdquo;.</section><section tabindex="-1"><h2>Future</h2>With the publication of the paper in Science Advances, Ollearo&rsquo;s work is all but finished. He will defend his thesis research on April 21. So, does the research stop there?&ldquo;No, certainly not. We want to see if we can further improve the device, for instance by making it quicker&rdquo;, says Janssen. &ldquo;We also want to explore whether we can clinically test the device, for instance in collaboration with the FORSEE project.&rdquo;The FORSEE project, led by TU/e researcher Sveta Zinger and in collaboration with the Catharina Hospital in Eindhoven, is&nbsp;<a href="https://www.tue.nl/en/news-and-events/news-overview/01-01-1970-smart-camera-reduces-unexpected-complications-in-hospitals/" target="_blank">developing an intelligent camera</a> that can observe a patient&rsquo;s heart and respiration rates.Let&rsquo;s hope the researchers at TU/e and TNO continue to prove that you don&rsquo;t need to be a Harry Potter to achieve amazing feats of science!<h3>More information</h3>Riccardo Ollearo, Ren&eacute; Janssen, Gerwin Gelinck et al. <a href="https://doi.org/10.1126/sciadv.adf9861" target="_blank">Vitality surveillance at distance using thin-film tandem-like narrowband near-infrared 2 photodiodes with light-enhanced responsivity</a>, Science Advances.This article was first published here:&nbsp;<a href="https://www.tue.nl/en/news-and-events/news-overview/17-02-2023-this-harry-potter-light-sensor-achieves-magically-high-efficiency-of-200-per-cent/" id="isPasted" rel="noopener noreferrer" target="_blank">https://www.tue.nl/en/news-and-events/news-overview/17-02-2023-this-harry-potter-light-sensor-achieves-magically-high-efficiency-of-200-per-cent/</a></section></section>

Researcher Riccardo Ollearo shows how the photodiode (right) picks up the signal from his finger, allowing him to see how fast his heart is beating on the screen (left). (Photo: Bart van Overbeeke)

Using green light and a double-layered cell, PhD researcher Riccardo Ollearo has come up with a photodiode that has sensitivity that many can only dream of.

This 'Harry Potter' light sensor achieves magically high efficiency of 200 per cent

Less than 15% of the 92 million tons of clothing and other textiles discarded annually are recycled&mdash;in part because they are so difficult to sort. Woven-in labels made with inexpensive photonic fibers, developed by a University of Michigan-led team, could change that.&ldquo;It&rsquo;s like a barcode that&rsquo;s woven directly into the fabric of a garment,&rdquo; said <a href="https://mse.engin.umich.edu/people/mshtein" target="_blank">Max Shtein</a>, U-M professor of materials science and engineering and corresponding author of the study in Advanced Materials Technologies. &ldquo;We can customize the photonic properties of the fibers to make them visible to the naked eye, readable only under near-infrared light or any combination.&rdquo;Ordinary tags often don&rsquo;t make it to the end of a garment&rsquo;s life&mdash;they may be cut away or washed until illegible, and tagless information can wear off. Recycling could be more effective if a tag was woven into the fabric, invisible until it needs to be read. This is what the new fiber could do.<img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1676377902069-PhotonicFibers1.jpg" style="width: 766px;" class="fr-fic fr-dib">Brian Iezzi scans and measures the photonic fibers in the fabric he developed. The laptop screen reflects the information he gathered. Photo: Marcin Szczepanski/Michigan Engineering&nbsp;Recyclers already use near-infrared sorting systems that identify different materials according to their naturally occurring optical signatures&mdash;the PET plastic in a water bottle, for example, looks different under near-infrared light than the HDPE plastic in a milk jug. Different fabrics also have different optical signatures, but <a href="https://shteinlab.engin.umich.edu/profile/brian-iezzi/" target="_blank">Brian Iezzi</a>, a postdoctoral researcher in Shtein&rsquo;s lab and lead author of the study, explains that those signatures are of limited use to recyclers because of the prevalence of blended fabrics.&ldquo;For a truly circular recycling system to work, it&rsquo;s important to know the precise composition of a fabric&mdash;a cotton recycler doesn&rsquo;t want to pay for a garment that&rsquo;s made of 70% polyester,&rdquo; Iezzi said. &ldquo;Natural optical signatures can&rsquo;t provide that level of precision, but our photonic fibers can.&rdquo;The team developed the technology by combining Iezzi and Shtein&rsquo;s photonic expertise&mdash;usually applied to products like displays, solar cells and optical filters&mdash;with the advanced textile capabilities at MIT&rsquo;s Lincoln Lab. The lab worked to incorporate the photonic properties into a process that would be compatible with large-scale production.<img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1676377925678-PhotonicFibers2.jpg" style="width: 766px;" class="fr-fic fr-dib">Brian Iezzi use his phone to simulate the scanning of the photonic fibers fabric he developed. In the future, one will be able to use their phone to read the clothing woven-in labels made with inexpensive photonic fibers. Photo: Marcin Szczepanski/Michigan Engineering&nbsp;They accomplished the task by starting with a preform&mdash;a plastic feedstock that comprises dozens of alternating layers. In this case, they used acrylic and polycarbonate. While each individual layer is clear, the combination of two materials bends and refracts light to create optical effects that can look like color. It&rsquo;s the same basic phenomenon that gives butterfly wings their shimmer.The preform is heated and then mechanically pulled&mdash;a bit like taffy&mdash;into a hair-thin strand of fiber. While the manufacturing process method differs from the extrusion technique used to make conventional synthetic fibers like polyester, it can produce the same miles-long strands of fiber. Those strands can then be processed with the same equipment already used by textile makers.By adjusting the mix of materials and the speed at which the preform is pulled, the researchers tuned the fiber to create the desired optical properties and ensure recyclability. While the photonic fiber is more expensive than traditional textiles, the researchers estimate that it will only result in a small increase in the cost of finished goods.&ldquo;The photonic fibers only need to make up a small percentage&mdash;as little as 1% of a finished garment,&rdquo; Iezzi said. &ldquo;That might increase the cost of the finished product by around 25 cents&mdash;similar to the cost of those use-and-care tags we&rsquo;re all familiar with.&rdquo;<img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1676377988942-PhotonicFibers3.jpg" style="width: 766px;" class="fr-fic fr-dib">Max Stein and Brian Iezzi analyze the fabric with photonic fibers woven into it. Photo: Marcin Szczepanski/Michigan Engineering&nbsp;Shtein says that in addition to making recycling easier, the photonic labeling could be used to tell consumers where and how goods are made, and even to verify the authenticity of brand-name products. It could be a way to add important value for customers.&ldquo;As electronic devices like cell phones become more sophisticated, they could potentially have the ability to read this kind of photonic labeling,&rdquo; Shtein said. &ldquo;So I could imagine a future where woven-in labels are a useful feature for consumers as well as recyclers.&rdquo;Iezzi worked closely with Lincoln Lab researchers Austin Coon, Lauren Cantley, Bradford Perkins, Erin Doran, Tairan Wang and Mordechai Rothschild to adapt the technology to a scalable, low-cost textile manufacturing process.<img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1676378024473-PhotonicFibers4.jpg" style="width: 766px;" class="fr-fic fr-dib">Brian Iezzi scans and measures the photonic fibers in the fabric he developed. Photo: Marcin Szczepanski/Michigan Engineering&nbsp;The team has applied for patent protection with the assistance of Innovation Partnerships at the University of Michigan and is evaluating ways to move forward with the commercialization of the technology.The research was supported by the United States National Science Foundation INTERN program (no. 1727894) and the Under Secretary of Defense for Research and Engineering under Air Force (no. FA8702-15-D-0001).

Max Stein and Brian Iezzi analyze the fabric with photonic fibers woven into it. Photo: Marcin Szczepanski/Michigan Engineering

Photonic fibers borrow from butterfly wings to enable invisible, indelible sorting labels.

A "game changer" for clothing recycling?

As technologies keep advancing at exponential rates and demand for new devices rises accordingly, miniaturizing systems into chips has become increasingly important. Microelectronics has changed the way we manipulate electricity, enabling sophisticated electronic products that are now an essential part of our daily lives. Similarly, integrated photonics has been revolutionizing the way we control light for applications such as data communications, imaging, sensing, and biomedical devices. By routing and shaping light using micro- and nanoscale components, integrated photonics shrinks full optical systems into the size of tiny chips.&nbsp;Despite its success, integrated photonics has been missing a key component to achieve complete miniaturization: high-performance chip-scale lasers. While some progress has been made on near-infrared lasers, the visible-light lasers that currently feed photonic chips are still benchtop and expensive. Since visible light is essential for a wide range of applications including quantum optics, displays, and bioimaging, there is a need for tunable and narrow-linewidth chip-scale lasers emitting light of different colors.&nbsp;<h2>Inventing high-performance lasers that fit on a fingertip</h2>Researchers at<a href="http://engineering.columbia.edu/" target="_blank">&nbsp;Columbia Engineering</a>&rsquo;s <a href="https://lipson.ee.columbia.edu/" target="_blank">Lipson Nanophotonics Group</a> have created visible lasers of very pure colors from near-ultraviolet to near-infrared that fit on a fingertip. The colors of the lasers can be precisely tuned and extremely fast &ndash; up to 267 petahertz per second, which is critical for applications such as quantum optics. The team is the first to demonstrate chip-scale narrow-linewidth and tunable lasers for colors of light below red -- green, cyan, blue, and violet. These inexpensive lasers also have the smallest footprint and shortest wavelength (404 nm) of any tunable and narrow-linewidth integrated laser emitting visible light. The <a href="https://www.nature.com/articles/s41566-022-01120-w" target="_blank">study</a>, which was first presented at the CLEO 2021 post-deadline session on May 14, 2021, was published online December 23, 2022, by&nbsp;Nature Photonics.&ldquo;What&rsquo;s exciting about this work is that we&rsquo;ve used the power of integrated photonics to break the existing paradigm that high-performance visible lasers need to be benchtop and cost tens of thousands of dollars,&rdquo; says the study&rsquo;s lead author Mateus Corato Zanarella, a PhD student who works with <a href="https://www.engineering.columbia.edu/faculty/michal-lipson" target="_blank">Michal Lipson</a>, Higgins Professor of <a href="https://www.ee.columbia.edu/" target="_blank">Electrical Engineering</a> and professor of <a href="https://www.apam.columbia.edu/" target="_blank">applied physics</a>. &ldquo;Until now, it&rsquo;s been impossible to shrink and mass-deploy technologies that require tunable and narrow-linewidth visible lasers. A notable example is quantum optics, which demands high-performance lasers of several colors in a single system. We expect that our findings will enable fully integrated visible light systems for existing and new technologies.&rdquo;&nbsp;<blockquote>What&rsquo;s exciting about this work is that we&rsquo;ve used the power of integrated photonics to break the existing paradigm that high-performance visible lasers need to be benchtop and cost tens of thousands of dollars.<footer>MATEUS CORATO ZANARELLA</footer><footer>LEAD AUTHOR OF THE STUDY AND PHD STUDENT IN THE LIPSON NANOPHOTONICS GROUP</footer></blockquote><section id="isPasted"><h2>Benefits of emitting wavelengths below red</h2>The importance of lasers emitting wavelengths shorter than red is clear when you consider some important applications. Displays, for example, require red, green, and blue light simultaneously to compose any color. In quantum optics, green, blue, and violet lasers are used for trapping and cooling atoms and ions. In underwater Lidar (Light Detection and Ranging), green or blue light is needed to avoid water absorption. However, at wavelengths shorter than red, the coupling and propagation losses of photonic integrated circuits increase significantly, which has prevented the realization of high-performance lasers at these colors.&nbsp;<h2>Solving coupling and propagation loss issues</h2>The researchers solved the coupling loss problem by choosing Fabry-Perot (FP) diodes as the light sources, which minimizes the impact of the losses on the performance of the chip-scale lasers. Unlike other strategies that use different types of sources, the team&rsquo;s approach enables the realization of lasers at record-short wavelengths (404 nm) while also providing scalability to high optical powers, FP laser diodes are inexpensive and compact solid-state lasers widely used in research and industry. However, they emit light of several wavelengths simultaneously and are not easily tunable, preventing them to be directly used for applications requiring pure and precise lasers. By combining them with the specially designed photonic chip, the researchers are able to modify the laser emission to be single-frequency, narrow-linewidth, and widely tunable.&nbsp;The team overcame the propagation loss issue by designing a platform that minimizes both the material absorption and surface scattering losses simultaneously for all the visible wavelengths. To guide the light, they used silicon nitride, a dielectric widely used in the semiconductor industry that is transparent for visible light of all colors. Even though there is minimal absorption, the light still experiences loss due to unavoidable roughness from the fabrication processes. The team solved this problem by designing a photonic circuit with a special type of ring resonator. The ring has a variable width along its circumference, allowing for single-mode operation characteristic of narrow waveguides, and low loss characteristic of wide waveguides. The resulting photonic circuit provides a wavelength-selective optical feedback to the FP diodes that forces the laser to emit at a single desired wavelength with very narrow linewidth.&ldquo;By combining these intricately designed pieces, we were able to build a robust and versatile platform that is scalable and works for all colors of light,&rdquo; said Corato Zanarella.&nbsp;<h2>Revolutionizing technologies</h2>&ldquo;As a laser manufacturer we recognize that integrated photonics will have a tremendous impact on our industry and will enable a new generation of applications that have so far been impossible,&rdquo; said Chris Haimberger, director of Laser Technology, TOPTICA Photonics, Inc. &ldquo;This work represents an important step forward in the pursuit of compact and tunable visible lasers that will power future developments in computing, medicine, and industry.&rdquo;The study&rsquo;s findings could revolutionize a broad range of applications, including:</section><section><a href="https://www.engineering.columbia.edu/news/high-performance-visible-light-lasers-fit-fingertip#" target="_blank"><ul><li> Quantum information</li></ul></a></section><section><a href="https://www.engineering.columbia.edu/news/high-performance-visible-light-lasers-fit-fingertip#" target="_blank"><ul><li>&nbsp;Atomic Clocks</li></ul></a></section><section><a href="https://www.engineering.columbia.edu/news/high-performance-visible-light-lasers-fit-fingertip#" target="_blank"><ul><li>&nbsp;Biosensing</li></ul></a></section><section><a href="https://www.engineering.columbia.edu/news/high-performance-visible-light-lasers-fit-fingertip#" target="_blank"><ul><li>&nbsp;Underwater Ranging</li></ul></a></section><section><a href="https://www.engineering.columbia.edu/news/high-performance-visible-light-lasers-fit-fingertip#" target="_blank"><ul><li style="font-weight: bold;">&nbsp;Li-Fi</li></ul></a></section><section><h2>Next steps</h2>The researchers, who have filed a provisional patent for their technology, are now exploring how to optically and electrically package the lasers to turn them into standalone units and use them as sources in chip-scale visible light engines, quantum experiments, and optical clocks.&ldquo;In order to move forward, we have to be able to miniaturize and scale these systems, enabling them to eventually be incorporated in mass-deployed technologies,&rdquo; said Lipson, a pioneer in silicon photonics whose research has strongly shaped the field from its inception decades ago, with foundational contributions in the active and passive devices that are part of any current photonic chip. She added, &ldquo;Integrated photonics is an exciting field that is truly revolutionizing our world, from optical telecommunications to quantum information to biosensing.&rdquo;</section>

Illustration of the integrated laser platform created by the Lipson Nanophotonics Group, where a single chip generates narrow linewidth and tunable visible light covering all colors. Credit: Myles Marshall/Columbia Engineering

In a significant advance for impactful technologies such as quantum optics and laser displays for AR/VR, Columbia Engineering’s Lipson Nanophotonics Group has invented the first tunable and narrow linewidth chip-scale lasers for visible wavelengths shorter than red.

High-performance Visible-light Lasers that Fit on a Fingertip

Printing objects from plastic precisely, quickly, and inexpensively is the goal of many 3D printing processes. However, speed and high resolution remain a technological challenge. A research team from the Karlsruhe Institute of Technology (KIT), Heidelberg University, and the Queensland University of Technology (QUT) has come a long way toward achieving this goal. It developed a laser printing process that can print micrometer-sized parts in the blink of an eye. The international team published the work in&nbsp;Nature Photonics. (DOI:&nbsp;<a href="https://www.nature.com/articles/s41566-022-01081-0" target="_blank">10.1038/s41566-022-01081-0</a>)Stereolithography 3D printing is currently one of the most popular additive manufacturing processes for plastics, both for private and industrial applications. In stereolithography, the layers of a 3D object are projected one by one into a container filled with resin. The resin is cured by UV light. However, previous stereolithography methods are slow and have too low a resolution. Light-sheet 3D printing, which is used by the KIT researchers, is a fast and high-resolution alternative.<h2>3D Printing with Two Colors in Two Stages</h2>In light-sheet 3D printing, blue light is projected into a container filled with a liquid resin. The blue light pre-activates the resin. In a second stage, a red laser beam provides the additional energy needed to cure the resin. However, 3D printing can only print quickly resins that quickly return from their pre-activated state to their original state. Only then can the next layer be printed. Consequently, the return time dictates the waiting time between two successive layers and thus the printing speed. &quot;For the resin we used, the return time was less than 100 microseconds, which allows for high printing speeds,&quot; says first author Vincent Hahn from KIT&#39;s Institute of Applied Physics (APH).<h2>Micrometer-sized Structures in Just the Blink of an Eye</h2>To take advantage of this new resin, the researchers built a special 3D printer. In this printer, blue laser diodes are used to project images into the liquid resin using a high-resolution display with a high frame rate. The red laser is formed into a thin &quot;light sheet&quot; beam and crosses the blue beam vertically in the resin. With this arrangement, the team was able to 3D print micrometer-sized parts in a few hundred milliseconds, i.e. in the blink of an eye. However, it should not stop there: &quot;With more sensitive resins, we could even use LEDs instead of lasers in our 3D printer,&quot; says Professor Martin Wegener of APH. &quot;Ultimately, we want to print 3D structures that are centimeters in size, while maintaining micrometer resolution and high printing speeds.&quot;The publication was produced within the framework of the joint &ldquo;3D Matter Made to Order&rdquo; Cluster of Excellence of the KIT and Heidelberg University. Junior Professor Dr Eva Blasco, a group leader at the Institute of Organic Chemistry and the Institute for Molecular Systems Engineering and Advanced Materials, was involved on the part of Heidelberg University.Original Publication: V. Hahn, P. Rietz, F. Hermann, P. M&uuml;ller, C. Barner-Kowollik, T. Schl&ouml;der, W. Wenzel, E. Blasco, and M. Wegener: Light-sheet three-dimensional microprinting via two-colour two-step absorption. Nature Photonics, 2022. DOI: 10.1038/s41566-022-01081-0 <a href="https://www.nature.com/articles/s41566-022-01081-0" target="_blank">https://www.nature.com/articles/s41566-022-01081-0</a><h2>Cluster of Excellence &quot;3D Matter Made to Order&rdquo;</h2>In the Cluster of Excellence &quot;3D Matter Made to Order,&quot; scientists from the Karlsruhe Institute of Technology (KIT) and Heidelberg University are conducting interdisciplinary research on innovative technologies and materials for digitally scalable additive manufacturing to improve the precision, speed, and performance of 3D printing. The goal of the work is to fully digitize 3D manufacturing and materials processing from the molecule to the microstructure. In addition to being funded as a Cluster of Excellence under the Excellence Strategy Competition of the German federal and state governments, &quot;3D Matter Made to Order&quot; is funded by the Carl Zeiss Foundation.Read more on the Cluster of Excellence<a href="https://www.3dmattermadetoorder.kit.edu/" target="_blank">&nbsp;&bdquo;3D Matter Made to Order&ldquo;</a><a href="https://www.materials.kit.edu/index.php" target="_blank">Details on the KIT Center Materials in Technical and Life Sciences</a>

In light sheet 3D printing, red and blue laser light is used to print objects precisely and quickly on a micrometer scale (Photo: Vincent Hahn, KIT)

Researchers from the Cluster of Excellence "3D Matter Made to Order" Print Microstructures by Crossing Red and Blue Laser Beams - Publication in Nature Photonics

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