Microscopy & Imaging News and Discussions

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Getting in gear: Researchers create a slow light device with high optical quality
https://phys.org/news/2022-01-gear-devi ... ality.html
by University of Massachusetts Amherst

Researchers including a postdoc at the University of Massachusetts Amherst have created a gear-shaped photonic crystal microring that increases the strength of light-matter interactions without sacrificing optical quality. The result is an on-chip microresonator with an optical quality factor 50 times better than the previous record in slow light devices that could improve microresonators used in a range of photonics applications, including sensing and metrology, nonlinear optics and cavity quantum electrodynamics.

Optical microresonators are structures that enhance light-matter interactions through a combination of long temporal confinement (i.e., high quality factor) and strong spatial confinement of an electromagnetic wave. The device the authors have developed in many ways integrates the best attributes of two types of optical microresonators—a photonic crystal and a whispering gallery mode resonator—in one device. While combining the two has been attempted in the past, previous microring devices that have succeeded in slowing light to increase interactions (a consequence of the photonic crystal) have had to sacrifice quality factor. In this new "microgear" photonic crystal ring, researchers observed modes with group velocity slowed down by 10 times relative to conventional microring modes without any degradation in quality factor.

The study, led by first author Xiyuan Lu and principal investigator Kartik Srinivasan, both from the National Institute of Standards and Technology (NIST) and the University of Maryland, appears in the January 2022 issue of Nature Photonics. UMass Amherst's Andrew McClung, a postdoc in the photonics lab of Amir Arbabi and a former NIST colleague of Lu, provided modeling and computer simulations for the work.

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Advanced photonic radar captures images down to the centimeter scale
By Michael Irving
February 07, 2022
https://newatlas.com/electronics/advanc ... ter-scale/

Researchers at the University of Sydney have developed a new type of radar that can measure objects down to centimeters. The new technique uses a photonic system to generate much higher bandwidth signals, enabling radar that can detect smaller objects more precisely, and even be used to monitor patient vital signs in hospitals.

Radar works by beaming radiofrequency signals out and analyzing how they bounce back, revealing the location, shape and speed of an object of interest, like a plane. Frequencies of a few hundred megahertz are most commonly used, which return images with a resolution on the scale of meters. Using higher frequencies could allow radar to capture finer detail, but that also widens the bandwidth. This requires far more powerful signal processing, in turn blowing out the cost and complexity of the system.

Photonic radar can help solve that problem. This technology still beams out microwaves, but the signals are generated and processed using lasers instead, giving them a much higher frequency over a wider bandwidth.

In the new study, the researchers developed an advanced photonic radar system that produced signals with a bandwidth of 11 GHz, centered on the frequency of 34 GHz. Importantly, the electronic components driving this operate at frequencies of just 40 to 80 MHz, keeping the system’s requirements simple. The resulting radar images have a much finer resolution, down to just 1.3 cm (0.5 in).

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Researchers combine piezoelectric thin film and metasurfaces to create lens with tunable focus
https://phys.org/news/2022-02-combine-p ... -lens.html
by The Optical Society

For the first time, researchers have created a metasurface lens that uses a piezoelectric thin film to change focal length when a small voltage is applied. Because it is extremely compact and lightweight, the new lens could be useful for portable medical diagnostic instruments, drone-based 3D mapping and other applications where miniaturization can open new possibilities.

"This type of low-power, ultra-compact varifocal lens could be used in a wide range of sensor and imaging technologies where system size, weight and cost are important," said research project leader Christopher Dirdal from SINTEF Smart Sensors and Microsystems in Norway. "In addition, introducing precision tunability to metasurfaces opens up completely new ways to manipulate light."

Dirdal and colleagues describe the new technology in the journal Optics Letters. To change focal length, a voltage is applied over lead zirconate titanate (PZT) membranes causing them to deform. This, in turn, shifts the distance between two metasurface lenses.

"Our novel approach offers a large displacement between the metasurface lenses at high speed and using low voltages," said Dirdal. "Compared to state-of-the-art devices, we demonstrated twice the out-of-plane displacement at a quarter of the voltage."

Combining technologies

The researchers made the new lens using metasurfaces—flat surfaces that are patterned with nanostructures to manipulate light. They are particularly interesting because they can integrate several functionalities into a single surface and can also be made in large batches using standard micro- and nanofabrication techniques at potentially low cost.

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Researchers develop large-field-of-view and high-resolution two-photon microscope
https://phys.org/news/2022-02-large-fie ... scope.html
by Li Yuan, Chinese Academy of Sciences

Two-photon microscopy (TPM) enables the observation of cellular and subcellular dynamics and functions in deep nervous tissues, providing critical in situ and in vivo information for understanding neurological mechanisms.

However, conventional TPM retains cellular resolution imaging over only a restricted field-of-view (FOV), usually 0.5 × 0.5 mm2, depending on the optical system. FOV is usually determined by objectives.

A research team led by Prof. Zheng Wei from the Shenzhen Institute of Advanced Technology (SIAT) of the Chinese Academy of Sciences proposed a novel method to extend the FOV of objectives and achieve high-resolution and large-FOV two-photon imaging.

The study was published in Optics Letters on Feb. 14.

Although several TPM systems have been reported with custom design objectives to achieve large FOV with high-resolution imaging, these systems need sophisticated design and assembly of customized optical components, which limits their wide applications.

The nominal FOV of objectives reflects the maximum imaging area where the optical aberration is considerably corrected. The team found that the incident light still could reach the area outside the nominal FOV of objectives (the extended FOV). However, when the signals from the extended FOV were used for imaging, the images were extremely blurred and distorted.

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New optical tweezers can control luminescent color using light pressure
https://phys.org/news/2022-02-optical-t ... ssure.html
by Osaka City University

One big stumbling block in the field of photonics is that of color control. Until now, to control color, i.e. the wavelength of light emission, researchers would have to alter the chemical structure of the emitter or the concentration of the solvent—all of which require direct contact, greatly limiting their application.

"Such conditions make it impossible to change color quickly, use it as a light source in microscopic spaces like a cell, or in closed systems where exchange is not an option," says Yasuyuki Tsuboi and professor of the Department of Chemistry, Osaka City University. With "optical tweezers," a technology he developed in previous research, Prof. Tsuboi led a team of researchers to show it possible to control the luminescence color remotely, using only the effect of light pressure.

Their findings were recently published online in the German international journal Angewandte Chemie.

For years, Professor Tsuboi and his colleagues have been conducting research on a technology that can capture and manipulate nano- and micrometer-sized materials with a laser. In exploring this "optical tweezers" technology, they found that when a silicon crystal with a special needle-shaped nanostructure, called black silicon, was submerged in a sample solution, the optical field enhancement effect of the nanostructure trapped a perylene-modified polymer, causing a local concentration of the solution to increase and form an aggregate of polymers.

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Ultra-compact integrated photonic device could lead to new optical technologies
https://phys.org/news/2022-03-ultra-com ... ogies.html
by University of Chicago

Photonic integrated circuits are essential to many technologies, including fiber-optic communications, mapping systems, and biosensors.

These circuits—which use photons instead of electrons—employ optical isolators that allow photons to travel in only one direction, which prevents light from re-entering the system and destabilizing it. But guiding light in one direction often requires large magnets, making these circuits difficult to create on a small scale.

Researchers at University of Chicago's Pritzker School of Molecular Engineering (PME) have developed a new way to guide light in one direction on a tiny scale. By coupling light confined in a nanophotonic waveguide with an atomically thin, two-dimensional semiconductor, the researchers exploited the properties of both the light and the material to guide photons in one direction.

The result – a small, tunable on-chip photonic interface – could lead to smaller photonic integrated circuits that could be more easily integrated into modern technologies, including computing systems and self-driving cars.

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A stretchy display for shapable electronics
https://techxplore.com/news/2022-03-str ... onics.html
by Stanford University

No one would ever imagine crumpling up their smartphone, television or another electronic device. Today's displays—which are flat, rigid and fragile—lack the ability to reshape to interactively respond to users.

As part of an overarching quest to build "skin-inspired" electronics that are soft and stretchy, Stanford University chemical engineer Zhenan Bao and her research team have been developing a display to change that. Now, after more than three years of work, they show the proof of principle toward a stretchable, potentially reshapable display in a new paper published March 23 in Nature.

Their invention hinges on the discovery of a method to produce a high-brightness elastic light-emitting polymer, which functions like a filament in a lightbulb. The group's resulting display is made entirely of stretchy polymers—synthetic plastic materials. The device has a maximum brightness at least two times that of a cellphone and can be stretched up to twice its original length without tearing.

"Stretchable displays can allow a new way of interactive human-machine interface," said Bao, the K. K. Lee Professor in the School of Engineering and senior author of the paper. "We can see the image and interact with it, and then the display can change according to our response."

An illuminating discovery

Most light-emitting polymers are stiff and crack when stretched. Scientists can increase their flexibility by adding elastic insulating materials, such as rubber. But these additives decrease electrical conductivity, which requires the polymer to use a dangerously high voltage to generate even dim light.

About three years ago, however, postdoctoral scholar Zhitao Zhang discovered that a yellow-colored light-emitting polymer called SuperYellow not only became soft and pliable but also emitted brighter light when mixed with a type of polyurethane, a stretchy plastic.

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Quantum 'shock absorbers' allow perovskite to exhibit superfluorescence at room temperature
https://phys.org/news/2022-03-quantum-a ... -room.html
by Tracey Peake, North Carolina State University
quote]

Semiconducting perovskites that exhibit superfluorescence at room temperature do so due to built-in thermal "shock absorbers" which protect dipoles within the material from thermal interference. A new study from North Carolina State University explores the mechanism involved in this macroscopic quantum phase transition and explains how and why materials like perovskites exhibit macroscopic quantum coherence at high temperatures.

Picture a school of fish swimming in unison or the synchronized flashing of fireflies—examples of collective behavior in nature. When similar collective behavior happens in the quantum world—a phenomenon known as macroscopic quantum phase transition—it leads to exotic processes such as superconductivity, superfluidity, or superfluorescenece. In all of these processes a group of quantum particles forms a macroscopically coherent system that acts like a giant quantum particle.

Superfluorescence is a macroscopic quantum phase transition in which a population of tiny light emitting units known as dipoles form a giant quantum dipole and simultaneously radiate a burst of photons. Similar to superconductivity and superfluidity, superfluorescence normally requires cryogenic temperatures to be observed, because the dipoles move out of phase too quickly to form a collectively coherent state.

Recently, a team led by Kenan Gundogdu, professor of physics at NC State and corresponding author of a paper describing the work, had observed superfluorescence at room temperature in hybrid perovskites.

"Our initial observations indicated that something was protecting these atoms from thermal disturbances at higher temperatures," Gundogdu says.[/quote]

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A new method to form a lens for atomic-resolution electron microscopes
https://phys.org/news/2022-04-method-le ... copes.html
by Tohoku University

Electron microscopy enables researchers to visualize tiny objects such as viruses, the fine structures of semiconductor devices, and even atoms arranged on a material surface. Focusing down the electron beam to the size of an atom is vital for achieving such high spatial resolution. However, when the electron beam passes through an electrostatic or magnetic lens, the rays of electrons exhibit different focal positions depending on the focusing angle and the beam spreads out at the focus. Correcting this "spherical aberration" is costly and complex, meaning that only a select few scientists and companies possess electron microscopes with atomic resolution.

Researchers from Tohoku University have proposed a new method to form an electron lens that uses a light field instead of the electrostatic and magnetic fields employed in conventional electron lenses. A ponderomotive force causes the electrons traveling in the light field to be repelled from regions of high optical intensity. Using this phenomenon, a doughnut-shaped light beam placed coaxially with an electron beam is expected to produce a lensing effect on the electron beam.

The researches theoretically assessed the characteristics of the light-field electron lens formed using a typical doughnut-shaped light beam—known as a Bessel or Laguerre-Gaussian beam. From there, they obtained a simple formula for focal length and spherical aberration coefficients which allowed them to determine rapidly the guiding parameters necessary for the actual electron lens design.

The formulas demonstrated that the light-field electron lens generates a "negative" spherical aberration which opposes the aberration of electrostatic and magnetic electron lenses. The combination of the conventional electron lens with a "positive" spherical aberration and a light-field electron lens that offset the aberration reduced the electron beams size to the atomic scale. This means that the light-field electron lens could be used as a spherical aberration corrector.

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Researchers Demonstrate Super-Resolution Microscopy

https://www.eurekalert.org/news-releases/949971

(EurekAlert) WASHINGTON — Researchers have developed a new measurement and imaging approach that can resolve nanostructures smaller than the diffraction limit of light without requiring any dyes or labels. The work represents an important advance toward a new and powerful microscopy method that could one day be used to see the fine features of complex samples beyond what is possible with conventional microscopes and techniques.

The new method, described in Optica, Optica Publishing Group’s journal for high-impact research, is a modification of laser scanning microscopy, which uses a strongly focused laser beam to illuminate a sample. The researchers expanded on the technique by measuring not only the brightness, or intensity, of the light after it interacts with a specimen under study, but also detecting other parameters encoded in the light field.

“Our approach could help extend the microscopy toolbox used to study nanostructures in a variety of samples,” said research team leader Peter Banzer from the University of Graz in Austria. “In comparison to super-resolution techniques based on a similar scanning approach, our method is fully non-invasive, meaning it doesn’t require any fluorescent molecules to be injected into a specimen before imaging.”

The researchers show that they can measure the position and sizes of gold nanoparticles with an accuracy of several nanometers, even when multiple particles were touching.

“Our novel approach to laser-scanning microscopy could close the gap between conventional microscopes with limited resolution and super-resolution techniques that require modification of the specimen under study,” said Banzer.

Here is a link to Optica: https://opg.optica.org/

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Real-time molecular imaging of near-surface tissue using Raman spectroscopy
https://medicalxpress.com/news/2022-04- ... issue.html
by Thamarasee Jeewandara , Medical Xpress

Modern imaging modalities have facilitated a steady progress in medicine and treatment of diseases. Among them, Raman spectroscopy has gained attention for clinical applications as a label-free, non-invasive method to deliver a molecular fingerprint of a sample. Researchers can combine such methods with fiber optic-probes to allow easy-access to a patient's body. However, it is still challenging to acquire images with fiber optic probes. In a new report published in Nature Light: Science & Applications, Wei Yang and a team of scientists, at the Leibniz Institute of Photonic Technology in Germany, developed a fiber optic probe-based Raman imaging system to visualize real-time, molecular, virtual reality data and detect chemical boundaries.

The researchers developed the process around a computer-vision based positional tracking system with photometric stereo and augmented and mixed chemicals for molecular imaging and direct visualization of molecular boundaries of three-dimensional surfaces. The method provided an approach to image large tissue areas in a few minutes, to distinguish clinical tissue-boundaries in a range of biological samples.

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'Metalens' could disrupt vacuum UV market
https://phys.org/news/2022-05-metalens- ... um-uv.html
by Rice University

Rice University photonics researchers have created a potentially disruptive technology for the ultraviolet optics market.

By precisely etching hundreds of tiny triangles on the surface of a microscopic film of zinc oxide, nanophotonics pioneer Naomi Halas and colleagues created a "metalens" that transforms incoming long-wave UV (UV-A) into a focused output of vacuum UV (VUV) radiation. VUV is used in semiconductor manufacturing, photochemistry and materials science and has historically been costly to work with, in part because it is absorbed by almost all types of glass used to make conventional lenses.

"This work is particularly promising in light of recent demonstrations that chip manufacturers can scale up the production of metasurfaces with CMOS-compatible processes," said Halas, co-corresponding author of a metalens demonstration study published in Science Advances. "This is a fundamental study, but it clearly points to a new strategy for high-throughput manufacturing of compact VUV optical components and devices."

Halas' team showed its microscopic metalens could convert 394-nanometer UV into a focused output of 197-nanometer VUV. The disc-shaped metalens is a transparent sheet of zinc oxide that is thinner than a sheet of paper and just 45 millionths of a meter in diameter. In the demonstration, a 394-nanometer UV-A laser was shined at the back of the disc, and researchers measured the light that emerged from the other side.

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A zero-cost way to improve neutron scattering resolution by 500%
https://phys.org/news/2022-05-zero-cost ... ution.html
by Paul Boisvert, Oak Ridge National Laboratory

Scientists pushing the limits of the world's most advanced neutron scattering instruments know that a small amount of distortion in their measurements is inevitable. For some experiments, this distortion is easily accounted for, but in other types of research it can cause inaccurate findings.

Why does a small amount of distortion matter? It's similar to when a detective lifts a fingerprint from a glass of water. The curvature of the glass distorts the fingerprint slightly, making it difficult to match the print to a suspect's fingerprint on file. In such a case, it would be helpful if there was a way to remove the distortion from the fingerprint found on the glass.

Something like this occurred when scientists from Oak Ridge National Laboratory (ORNL) used the world-class SEQUOIA neutron scattering spectrometer at ORNL's Spallation Neutron Source (SNS). The researchers were measuring spin wave dispersions from a magnetic crystalline material. They discovered that the data (the fingerprint) obtained from SEQUOIA (the glass) was slightly distorted by the resolution limits of the instrument, despite its state-of-the-art design.

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Light traveling in a distorting medium can appear undistorted
https://phys.org/news/2022-06-distortin ... orted.html
by Wits University

A team led by researchers at the University of the Witwatersrand in Johannesburg, South Africa, with collaborators from the University of Pretoria (South Africa), as well as Mexico and Scotland, have made a new discovery on how light behaves in complex media, media that tends to distort light significantly. They demonstrated that "distortion" is a matter of perspective, outlining a simple rule that applies to all light and a vast array of media, including underwater, optical fiber, transmission in the atmosphere and even through living biological samples.

Their novel quantum approach to the problem resolves a standing debate on whether some forms of light are robust or not, correcting some misconceptions in the community. Importantly, the work outlines that all light has a property that remains unchanged, an insight that holds the key to unraveling the rest of the perceived distortion. To validate the finding, the team showed robust transport through otherwise highly distorting systems, using the outcome for error-free communication through noisy channels.

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New single-mode semiconductor laser delivers power with scalability
https://phys.org/news/2022-06-single-mo ... ility.html
by University of California - Berkeley

Berkeley engineers have created a new type of semiconductor laser that accomplishes an elusive goal in the field of optics: the ability to maintain a single mode of emitted light while maintaining the ability to scale up in size and power. It is an achievement that means size does not have to come at the expense of coherence, enabling lasers to be more powerful and to cover longer distances for many applications.

A research team led by Boubacar Kanté, Chenming Hu Associate Professor in UC Berkeley's Department of Electrical Engineering and Computer Sciences (EECS) and faculty scientist at the Materials Sciences Division of the Lawrence Berkeley National Laboratory (Berkeley Lab), showed that a semiconductor membrane perforated with evenly spaced and same-sized holes functioned as a perfect scalable laser cavity. They demonstrated that the laser emits a consistent, single wavelength, regardless of the size of the cavity.

The researchers described their invention, dubbed Berkeley Surface Emitting Lasers (BerkSELs), in a study published Wednesday, June 29, in the journal Nature.

"Increasing both size and power of a single-mode laser has been a challenge in optics since the first laser was built in 1960," said Kanté. "Six decades later, we show that it is possible to achieve both these qualities in a laser. I consider this the most important paper my group has published to date."

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World's first self-calibrated photonic chip: An interchange for optical data superhighways
https://phys.org/news/2022-07-world-sel ... hange.html
by Monash University

Research led by Monash and RMIT Universities in Melbourne has found a way to create an advanced photonic integrated circuit that builds bridges between data superhighways, revolutionizing the connectivity of current optical chips and replacing bulky 3D-optics with a wafer thin slice of silicon.

This development, published in the journal Nature Photonics, has the ability to warp-speed the global advancement of artificial intelligence and offers significant real world applications such as:

Safer driverless cars capable of instantly interpreting their surroundings
Enabling AI to more rapidly diagnose medical conditions
Making natural language processing even faster for apps such as Google Homes, Alexa and Siri
Smaller switches for reconfiguring optical networks that carry our internet to get data where it's needed faster

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A new way of fabricating high-efficiency diffraction gratings for astronomical spectroscopy
https://phys.org/news/2022-11-fabricati ... scopy.html
by SPIE

Today, astronomers seek to observe the faintest and most distant objects possible. Extremely Large Telescopes (ELTs), with apertures in the order of several dozen meters, are the next generation facilities to do so. However, building larger telescopes is only one part of the equation. The other part is the capability of detecting the gathered photons in the most efficient way possible.

This is where making all other optical components in astronomical instruments more efficient becomes crucial. One essential component used in modern astronomical science is the diffraction grating. Its role is to spatially spread incoming light into its constituent frequencies, similar to how a glass prism does.

Thanks to a precisely engineered structure that leverages the wave-like nature of photons, diffraction gratings can separate light of different wavelengths with very high resolution. When coupled with a telescope and a spectrometer, gratings allow scientists to analyze the spectral properties of celestial bodies.

Motivated by the somewhat stagnant progress made in grating technology over the past decade, researchers Hanshin Lee of the University of Texas at Austin and Menelaos K. Poutous of the University of North Carolina at Charlotte, focused on a completely different way of fabricating diffraction gratings.

In their paper recently published in the Journal of Astronomical Telescopes, Instruments, and Systems, they report their success on manufacturing proof-of-concept high-efficiency diffraction gratings using reactive ion-plasma etching (RIPLE), a plasma-based manufacturing technology normally used for semiconductors.

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New photoacoustic microscopy technique achieves depth of field nearly 14 times greater than previous technology
https://medicalxpress.com/news/2022-12- ... field.html
by Emily Velasco, California Institute of Technology

Photoacoustic microscopy (PAM) is a relatively new imaging technique that uses laser light to induce ultrasonic vibrations in tissue. These ultrasonic vibrations, along with a computer that processes them, can then be used to create an image of the structures of the tissue in much the same way ultrasound imaging works.

In the last few years, Lihong Wang, Caltech's Bren Professor of Medical Engineering and Electrical Engineering, has developed PAM technologies that can image changing blood flow in the brain, detect cancerous tissue, and even identify individual cancer cells.

However, one limitation of high-resolution (i.e., optical-resolution) PAM has been its narrow depth of field, meaning that it can only focus on a thin layer (approximately 30 micrometers, or about the length of one skin cell, with one to two micrometers of resolution) of tissue at a time. To see something above or below the plane that the device is viewing, it needs to refocus above or below that plane. For comparison, imagine a person putting on reading glasses to do a crossword puzzle.

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Ultrafast control of spins in a microscope
https://phys.org/news/2023-01-ultrafast-microscope.html
by Nik Papageorgiou, Ecole Polytechnique Federale de Lausanne

Researchers at EPFL have developed a new technique that can visualize and control the rotation of a handful of spins arranged in a vortex-like texture at the fastest speed ever achieved. The breakthrough can advance "spintronics," a technology that includes new types of computer memory, logic gates, and high-precision sensors.

"Technological advancements in computation, data storage and sensing all require new techniques to control the nanoscaled magnetic properties of materials," says Professor Fabrizio Carbone at EPFL's School of Basic Sciences. One of these properties is "spin," which refers to the magnetic orientation of individual atoms.

Spin has attracted a lot of interest in recent years, giving rise to the field of spin electronics or "spintronics." Apart from the fundamental study of spin, the more practical aim of spintronics is to exploit not just the charge of electrons—as in traditional electronics—but also their spin, adding and extra degree of freedom that can improve the efficiency of data storage and transfer.

However, this first requires that we can control small numbers of spins. "The visualization and deterministic control of very few spins has not yet been achieved at the ultrafast timescales," says Dr. Phoebe Tengdin, a postdoc in Carbone's lab, pointing out the very tight timeframes that this control needs to happen for spintronics to ever make the leap into applications.

Now, Tengdin along with Ph.D. student Benoit Truc and fellow postdoc Dr. Alexey Sapozhnik have developed a new technique that can visualize and control the rotation of a handful of spins arranged in a vortex-like texture, a kind of spin "nano-whirlpool" called a skyrmion.

To do this, the scientists used sequences of laser pulses at a femtosecond timeframe (10-15 or a quadrillionth of a second). By arranging the laser pulses apart just right, they were able to control the rotation of spins in a selenium-copper mineral known in the field by its chemical composition, Cu2OSeO3. The mineral is quite popular in the field of spintronics, as it provides an ideal testbed for studying spins.

Controlling the spins with laser pulses, the researchers found that they could even switch their orientation at will by simply changing the delay time between successive driving pulses and adjusting the laser polarization.

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Researchers devise new membrane mirrors for large space-based telescopes
https://phys.org/news/2023-04-membrane- ... copes.html
by Optica

Researchers have developed a new way to produce and shape large, high-quality mirrors that are much thinner than the primary mirrors previously used for telescopes deployed in space. The resulting mirrors are flexible enough to be rolled up and stored compactly inside a launch vehicle.

"Launching and deploying space telescopes is a complicated and costly procedure," said Sebastian Rabien from Max Planck Institute for Extraterrestrial Physics in Germany. "This new approach—which is very different from typical mirror production and polishing procedures—could help solve weight and packaging issues for telescope mirrors, enabling much larger, and thus more sensitive, telescopes to be placed in orbit."

In the journal Applied Optics, Rabien reports successful fabrication of parabolic membrane mirror prototypes up to 30 cm in diameter. These mirrors, which could be scaled up to the sizes needed in space telescopes, were created by using chemical vapor deposition to grow membrane mirrors on a rotating liquid inside a vacuum chamber. He also developed a method that uses heat to adaptively correct imperfections that might occur after the mirror is unfolded.

"Although this work only demonstrated the feasibility of the methods, it lays the groundwork for larger packable mirror systems that are less expensive," said Rabien. "It could make lightweight mirrors that are 15 or 20 meters in diameter a reality, enabling space-based telescopes that are orders of magnitude more sensitive than ones currently deployed or being planned."