Touchless Print Scanning...

Credit: N. Hanacek/NIST NIST evaluated several commercially available contactless fingerprint scanning technologies in its May 2020 report.

Topics: NIST, Optics, Research

The National Institute of Standards and Technology (NIST) has evaluated several commercially available contactless fingerprint scanning technologies, allowing users to compare their performance to conventional devices that require physical contact between a person’s fingers and the scanner.

The results of the study, published today as NIST Interagency Report (NISTIR) 8307: Interoperability Assessment 2019: Contactless-to-Contact Fingerprint Capture, show that devices requiring physical contact remain superior to contactless technology at matching scanned prints to images in a database. However, when contactless devices scan multiple fingers on a hand, it improves their performance. Contactless devices that scanned multiple fingers also seldom made “false positive” errors that incorrectly matched one person’s print with another’s record.

The publication updates NIST’s July 2018 study on contactless capture and is intended to assist organizations that use fingerprint-scanning technology.

“The report summarizes the state of the art of contactless fingerprint scanning,” said John Libert, one of the report’s authors. “It can help anyone interested in adopting contactless technology to evaluate the cost in performance they might pay by switching to contactless fingerprint capture.”

NIST Study Measures Performance Accuracy of Contactless Fingerprinting Tech

Silicon Sees the Light...

Silicon sees the light: Elham Fadaly (left) and Alain Dijkstra in their Eindhoven lab. (Courtesy: Sicco van Grieken/SURF)

Topics: Optics, Electrical Engineering, Nanotechnology, Research, Solar Power, Spectroscopy

A light-emitting silicon-based material with a direct bandgap has been created in the lab, fifty years after its electronic properties were first predicted. This feat was achieved by an international team led by Erik Bakkers at Eindhoven University of Technology in the Netherlands. They describe the new nanowire material as the “Holy Grail” of microelectronics. With further work, light-emitting silicon-based devices could be used to create low-cost components for optical communications, computing, solar energy and spectroscopy.

Silicon is the wonder material of electronics. It is cheap and plentiful and can be fabricated into ever smaller transistors that can be packed onto chips at increasing densities. But silicon has a fatal flaw when it comes to being used as a light source or solar cell. The semiconductor has an “indirect” electronic bandgap, which means that electronic transitions between the material’s valence and conduction bands involve vibrations in the crystal lattice. As a result, it is very unlikely that an excited electron in the conduction band of silicon will decay to the valence band by emitting light. Conversely, the absorption of light by silicon does not tend to excite valence electrons into the conduction band – a requirement of a solar cell.

Silicon-based light emitter is ‘Holy Grail’ of microelectronics, say researchers
Hamish Johnston, Physics World

Hologram Printer...

The new printer uses low-power continuous wave lasers to create holograms on a highly sensitive photomaterial developed by the researchers. Credit: C Yves GENTET

Topics: 3D Objects, 3D Printing, Applied Physics, Holograms, Optics, Research

Researchers have developed a new printer that produces digital 3-D holograms with an unprecedented level of detail and realistic color. The new printer could be used to make high-resolution color recreations of objects or scenes for museum displays, architectural models, fine art or advertisements that do not require glasses or special viewing aids.

"Our 15-year research project aimed to build a hologram printer with all the advantages of previous technologies while eliminating known drawbacks such as expensive lasers, slow printing speed, limited field of view and unsaturated colors," said research team leader Yves Gentet from Ultimate Holography in France. "We accomplished this by creating the CHIMERA printer, which uses low-cost commercial lasers and high-speed printing to produce holograms with high-quality color that spans a large dynamic range."

New printer creates extremely realistic colorful holograms, The Optical Society, Phys.org

How We See the Small...

View of cantilever on an atomic force microscope (magnification 1000x).
Credit: SecretDisc GFDL, CC-BY-SA-3.0

Topics: Atomic Force Microscopy, Nanotechnology, Optics, Scanning Electron Microscope

Cell reproduction, disease detection and semiconductor optimization are just some of the areas of research that have exploited the atomic force microscope. First invented by Calvin Quate, Gerd Binnig and Christoph Gerber in the mid 1980s, atomic force microscopy (AFM) brought the atomic resolution recently achieved by the scanning tunnelling microscope to non-conducting samples, and helped to catalyse the avalanche of science and technology based on nanostructures that now permeates all aspects of modern life from smartphones to tennis rackets. On 6 July 2019 Calvin Quate died aged 95 at his home in Menlo Park, California.

Long before the development of AFM, Quate’s research had made waves in microscopy. 1978 had seen the announcement of the scanning acoustic microscope, which achieved the sensitivity of optical microscopy but probed samples so softly that it could image the interiors of living cells without damaging them. The technique uses high frequency sound waves in place of light, which penetrate deep into structures to image internal structures non-destructively. It is widely used in quality control of electronic component assembly among other applications such as printed circuit boards and medical products.

Advanced microscopy pioneer leaves broad ranging legacy
Anna Demming, Physics World

Fiber Optics Pioneer Passes...

Image Source: Link below

Topics: Diversity, Diversity in Science, History, Internet, Nobel Prize, Optics

Charles Kao, the electrical engineer who shared the 2009 Nobel Prize for Physics with Willard Boyle and George Smith, has died in Hong Kong aged 84. Kao was awarded half of the 2009 prize “for ground-breaking achievements concerning the transmission of light in fibres for optical communication.”

Kao was born on 4 November 1933 in Shanghai, China. He studied electrical engineering at Woolwich Polytechnic (now the University of Greenwich) and received his PhD in electrical engineering from University College London in 1965 under the supervision of Harold Barlow. While pursuing his PhD, he was employed by Standard Telephones and Cables (STC) at the firm’s Standard Telecommunication Laboratories (STL) in Harlow, UK.

While working at STL in 1966, Kao realized that optical fibres made from high-purity glass could be used to transmit light signals over long distances. A few years later, he showed that fibres made of fused silica had the required purity and could also be easily manufactured. This was a crucial step towards the development of fibre-optical telecoms networks, which provide the backbone to the Internet.

Optical telecoms pioneer and Nobel laureate Charles Kao dies at 84
Hamish Johnston, Physics World

Mesh and Eyes...

Schematic showing nonsurgical injection of mesh electronics into the vitreous body of the eye, allowing conformal coating of the mesh on the surface of retina for electrophysiological recording of individual retinal ganglion cells in live animals. Credit: Lieber Group, Harvard University. All rights reserved

Topics: Biology, Materials Science, Optics, Research

Mesh electronics, a macroporous network of components with mechanical properties similar to that of biological tissue, is a relatively new technology that can be used to probe activity in the brain. Now, researchers at Harvard University in the US have developed an injectable mesh that can record the neural activity of mouse eyes in vivo. The device, which does not interfere with eye movement or light-processing, could help neuroscientists study the fundamental properties of primary vision input retinal ganglion cells (RGCs) and how these cells connect with other vision-related brain regions for the first time. The work could also help in the development of retinal prosthetics for restoring vision through non-surgical procedures.

“Mesh electronics is a submicron-thick, large-area macroporous network,” explains team leader Charles Lieber. “We fabricate the meshes as flat 2D sheets using standard semiconductor photolithography-based techniques and suspend them (like a colloid) in aqueous solution. Our specific design, which we first reported on back in 2015, enables mesh electronics to be rolled up into a tubular structure and drawn into a syringe needle.”

On the scale of a single neuron

“We can deliver these structures into specific brain regions with a spatial precision of 20 microns (which is on the scale of a single neuron) using the controlled injection approach we developed. This allows us to control the rate at which we withdraw the needle during injection and means that the mesh structure remains fully extended in the dense tissue of the brain during injection and does not crumple.”

In their new work Lieber and colleagues “non-coaxially” injected the mesh electronics onto the highly curved retinal cup of the eye. As the structure unrolls it forms a stable recording interface to RGCs, which process visual information received by photoreceptors (rods and cones). The researchers then did a series of experiments.

Injectable mesh electronics opens up a new window into vision research
Belle Dumé, Physics World

Nanophotonics and Darkness...

A finite photonic crystal nanostructure in free space. The photonic crystal consists of periodic arrangements of pores in a semiconductor material such as silicon (shown in grey) that are being fabricated in Twente. Light noise in the surrounding free space is shown as the red wavelets. For a range of colours of light (known as the photonic band gap), the light noise is forbidden from entering the crystal, thus leading to strong darkness. The question solved in Twente is: How fast is absolute darkness reached while making the nanostructure larger and larger? Courtesy: University of Twente

Topics: Applied Physics, Nanotechnology, Optics, Photonics

Just as there is no such thing as a complete vacuum, there is no such thing as complete darkness. This is because there are always continuous fluctuations of light in space, also known as light noise. Theory predicts that this light noise might be completely eliminated in photonic crystals, however, so allowing them to become absolutely dark.

Photonic crystals are nanostructured materials in which a periodic variation of the refractive index on the length scale of visible light produces a photonic “band gap”. This gap affects how photons propagate through the material and is similar to the way in which a periodic potential in semiconductors affects the flow of electrons by defining allowed and forbidden energy bands. In the case of photonic crystals, light of certain wavelength ranges can pass through the photonic band gap while light in other ranges is reflected.

Photonic crystals follow a straight path to absolute darkness, Belle Dumé, Physics World

Combing for Earths...

An example of the spectrum from two laser frequency combs, with their evenly spaced emission lines. (Courtesy: ESO).

Topics: Astronomy, Astrophysics, Exoplanets, Optics, Space Exploration

A new type of laser frequency comb (LFC) has been developed by scientists in Europe. The prototype device could lead to improvements in how scientists search for Earth-like exoplanets, measure the expansion of the Universe and test the fundamental constants of nature.

LFCs produce spectral lines of light with evenly spaced frequencies and have a wide range of applications in metrology and spectroscopy. The new LFC was developed by Tobias Herr of the Swiss Centre for Electronics and Microtechnology, Francesco Pepe of the Geneva Observatory and colleagues. It uses a laser-driven microresonator on a silicon-nitride chip that produces 24 GHz pulses for use in calibrating near-infrared spectrometers. This gives it an advantage over traditional LFCs, which operate at frequencies below 10 GHz and create a line spacing that is too small for astronomical spectroscopy.

The pulses are produced by way of a phenomenon known as temporal dissipative Kerr-cavity solitons (DKSs), which involves trapping ultra-short pulses of light in a circular, micron-sized microresonator. Each time the DKS pulse passes the microresonator’s input-output coupler, some of the pulse is siphoned away and directed towards the spectrometer, producing a series of spectral lines that, in the prototype, are each precisely 24 GHz apart. These lines form a spectral comb and act as a precise calibration tool for the spectrometer.

One popular method of detecting exoplanets is the radial velocity technique. This involves measuring a star’s subtle motion that is caused by the gravitational tug of an orbiting planet. These motions are often no faster than walking pace and require highly accurate spectroscopic measurements of the Doppler shift in the star’s light as it moves. The size of the Doppler shift and the period at which it occurs can tell astronomers both the mass and the distance from the star of the planet. The greater the mass of the star, or the less massive or more distant the planet, the smaller the Doppler shift.

Optical ‘astrocomb’ could boost searches for Earth-like planets, Keith Cooper, Physics World

Darkest Black...

Image Source: CNET: Sci-Tech

Topics: Carbon Nanotubes, Materials Science, Nanotechnology, Optics

The Science of Vantablack

The name Vantablack® stands for Vertically Aligned Nanotube Array black.

Vantablack is a free-space coating consisting of a 'forest' of aligned and equally spaced, high aspect-ratio carbon nanotubes (CNTs).

The CNT array is patterned and spaced to allow photons to enter. Most of the light, or radiation arriving at the surface enters the space between the CNTs, and is repeatedly reflected between tubes until it is absorbed and converted to heat. This heat (largely undetectable in most applications) is conducted to the substrate and dissipated. The Vantablack array is very largely free-space; the volume of CNTs only makes up about 0.05% of the coating. Consequently, only a minuscule proportion of the incident radiation is able to hit the tip of a CNT, explaining why such a small amount is reflected back to the observer.

Vantablack's exceptional properties

Ultra low reflectance - Vantablack absorbs 99.965% of light (750nm wavelength)

UV, Visible and IR absorption - Absorption works from UV (200-350 nm wavelength), through the visible (350-700nm) and into the far infrared (>16 microns) spectrum, with no spectral features.

Very high front to back thermal conduction - excellent for Black Body calibration sources

Super hydrophobic - Unlike other black coatings, water has no impact on the optical properties

Very high thermal shock resistance - Repeatedly plunging a Vantablack coated substrate into liquid Nitrogen at -196°C and then transferring to a 300°C hot plate in air does not affect its properties.

Resistant to extreme shock and vibration - Independently tested, Vantablack has been subjected to severe shocks and vibration simulating launch and staging.

Information Source: Surrey Nanosystems

Single Atom Magnifier...

Artist's impression of nanophotonics. Courtesy: NanoPhotonics Cambridge/Bart deNijs.

Topics: Nanotechnology, Optics, Picocavity

Researchers in the UK and Spain have succeeded in confining light to a volume smaller than the size of a single atom for the first time – a feat that seemed completely impossible even just a few years ago. The “picocavity”, which can be thought of as the world’s smallest magnifying glass, could be used to study how light and matter interact at tiny scales and even to observe individual chemical bonds forming and breaking between atoms. The cavity might also be used to make new optomechanical data storage devices in which information can be written and read by light and stored in the form of molecular vibrations.

For a long time, scientists thought that visible light could not be focused to less than half its wavelength – the so-called diffraction limit. In recent years, however, they have learnt how to use nanostructured metals like gold and silver that support surface plasmons (oscillations of electrons at the metal surface) to confine optical fields to much smaller than their wavelength.

Now, a team led by Jeremy Baumberg at Cambridge University in the UK has used highly conductive gold nanoparticles to make the world’s tiniest optical cavity. This cavity is so small that only a single atom can fit in it. “We will never do any better than this!” says Baumberg.

Nanotechweb: Picocavity confines light to smallest volume ever, Belle Dumé

For Eleanor...

OSA sponsors multiple programs to promote optics and photonics among K-12 students.

Legacy programs include the Optics Discovery Kit and the Optics Suitcase. Online, OSA sponsors the Optics4Kids site which provides information and educational resources. (iStock.com$#92;VYCHEGZHANINA)

(Courtesy of iStock.com\VYCHEGZHANINA)*

Topics: Diversity in Science, Einstein, Electromagnetism, James Clerk Maxwell, Laser, Modern Physics, Optics, Quantum Mechanics, Women in Science

"It is better to light a candle than curse the darkness." Eleanor Roosevelt

In June 1916, exactly one century ago, Albert Einstein predicted the existence of ripples, known as gravitational waves, in the fabric of spacetime. Earlier this year we celebrated the stunning observation of the phenomenon by a worldwide collaboration of more than 1000 scientists using incredibly sensitive antennas built of mirrors and lasers. (See Physics Today, April 2016, page 14.) As with many scientific achievements, this recent milestone draws on innumerable theoretical, observational, and technological innovations and iterations made along the way. It’s worth reflecting on the vast body of knowledge the scientific community has generated, the breakthrough technologies that have allowed us to observe our world with ever-greater depth and precision, and the people who have dedicated their lives and careers to expanding knowledge and applications in diverse branches of science.

This year marks the 100th anniversary of The Optical Society, a worldwide community for optics and photonics professionals and students. Over the past century, the research world and consumers alike enjoyed a dramatic expansion of light-based science and applied technology. In many ways, the growth of optics and photonics has mirrored the birth and expansion of modern physics from the early 20th century through today. Applied optics and spectroscopy have long played a central role in enabling new discoveries in physics; that new physics has fueled advances in optics and photonics that, in turn, have created powerful tools for the study of space, time, and matter. The laser, for instance, has become an indispensable tool of scientific inquiry. Solid-state detectors of incredible density and sensitivity are used for scientific imaging from telescopes on Earth to cameras on Mars. Innovations in laser cooling have given us unprecedented access to the quantum world, and laser frequency comb technology has greatly expanded precision measurements for both fundamental and applied sciences.

But that list is far from complete. This article permits only a sparse survey of the noteworthy advances and trailblazers from the past century of optics and of the innumerable benefits we derive from them. Further highlights are available on the OSA Centennial webpage at www.osa.org/en-us/100/osa100*.

Physics Today: A century of light, Anne Frances Johnson and Nancy D. Lamontagne

Light-Effect Transistor...

Image Source: MIT Technology Review

Topics: Consumer Electronics, Electrical Engineering, Economy, Nanotechnology, Optics, STEM

This caught my eye working in the industry, especially since the doping of silicon or germanium substrates requires the introduction of impurities at high energies and many of them poisonous to humans, hence the great control we use in manufacture. My guess (or, my hope) is this will in some extent prove cleaner as well as cheaper to produce.

TECHNOLOGY REVIEW: The field effect transistor is the workhorse of the consumer electronics industry. Carved into microchips in the billions, these devices beaver away, more or less unnoticed, in practically every home, office, and laboratory in the developed world.

And yet there is a perennial problem with field effect transistors that keeps chip designers awake at night—how to make them ever smaller and thereby keep up the relentless pace of Moore’s Law.

These silicon layers have to be doped with other atoms—just a handful will do the trick in such small components. And therein lies the problem. Even small random variation in the number of dopant atoms in semiconductor components can have a huge effect on the behavior of the transistor. How to control these variations during manufacture is by no means clear. Then there is the physical problem of making a device with three terminals even smaller.

Today, Jason Marmon at University of North Carolina in Charlotte and a few pals unveil just such a device in the form of a light effect transistor. This is essentially a wire that conducts when it is bathed in light and insulates when it is dark. In other words, it is a switch modulated by light. The team says its new device is simpler than a field effect transistor and does not rely on dopant atoms, so it can be made smaller and thereby continue Moore’s law.

Abstract

Modern electronics are developing electronic-optical integrated circuits, while their electronic backbone, e.g. field-effect transistors (FETs), remains the same. However, further FET down scaling is facing physical and technical challenges. A light-effect transistor (LET) offers electronic-optical hybridization at the component level, which can continue Moore's law to the quantum region without requiring a FET's fabrication complexity, e.g. a physical gate and doping, by employing optical gating and photoconductivity. Multiple independent gates are therefore readily realized to achieve unique functionalities without increasing chip space. Here we report LET device characteristics and novel digital and analog applications, such as optical logic gates and optical amplification. Prototype CdSe-nanowire-based LETs show output and transfer characteristics resembling advanced FETs, e.g. on/off ratios up to ~1.0x10^6 with a source-drain voltage of ~1.43 V, gate-power of ~260 nW, and subthreshold swing of ~0.3 nW/decade (excluding losses). Our work offers new electronic-optical integration strategies and electronic and optical computing approaches.

Physics arXiv:
Light-effect transistor (LET) with multiple independent gating controls for optical logic gates and optical amplification
Jason K. Marmon, Satish C. Rai, Kai Wang, Weilie Zhou, Yong Zhang

Sunset...

Light-based technologies wowed the crowds at Lightfest in Birmingham, UK, a celebration of light in science, art, technology and culture held in conjunction with IYL 2015. Visit Physics World Showcase: Light to see a video of the event and other light-themed videos.

Topics: Lasers, Optical Physics, Optics

The International Year of Light and Light-based Technologies (IYL 2015) will soon draw to a close, in a year that has seen thousands of events celebrating the science and applications of light in more than a 100 countries worldwide. Officially launched in January at the headquarters of the UN Educational, Scientific and Cultural Organization (UNESCO) in Paris, IYL 2015 has involved more than 100 partners from 85 countries – including the Institute of Physics, which publishes Physics World.

A range of international and national events have been held, touching on light in everything from archaeology and communications to medicine and the arts. The Light: Beyond the Bulb project, for example, has put the science of light into public settings around the world, such as parks, metro-stations, airports and libraries, while the Study after Sunset initiative promoted the use of solar-powered light-emitting-diode (LED) lanterns in parts of the world where there is little or no reliable source of light after dark. The iSPEX-EU campaign has used "citizen science" to measure air pollution with smartphones; while children, teachers, scientists and artists from more than 25 countries came together to write the "SkyLight" science opera.

Physics World: International Year of Light Draws to a Close, Michael Banks
#P4TC: International Year of Light

Quantum Dot Photodetector...

Andrew Fidler of Los Alamos National Laboratory examines an ultrafast photodetector used to measure quantum-dot carrier multiplication in real time. Courtesy: V Klimov

Topics: Nanotechnology, Optics, Quantum Dots, Quantum Mechanics, Semiconductor Technology

Researchers at the Los Alamos National Laboratory in the US have developed the first ultrafast photodetector made from quantum dots that is capable of directly observing the extra electrons produced via “carrier multiplication” – the process by which multiple electrons are generated by a single photon. The result could help in the development of more efficient solar cells and new types of photo and radiation detectors.

When a conventional solar cell or photodetector absorbs a single photon, a single electron-hole pair (or exciton) is generated. However, in quantum dots (which are small pieces of semiconductor just several nanometres in size), electrons can efficiently interact with each other after they have absorbed light, generating multiple electrons from a single photon. This effect is known as carrier multiplication, and could help make cheaper and more efficient solar cells as well as new types of photodetectors.

Nanotechweb.org:
Ultrafast quantum-dot photodetector detects multiple electrons, Belle Dumé

Molecules of Light...

Researchers show that two photons, depicted in this artist’s conception as waves (left and right), can be locked together at a short distance. Under certain conditions, the photons can form a state resembling a two-atom molecule, represented as the blue dumbbell shape at center.

Credit: E. Edwards/JQI

Topics: Optics, Physics Humor, Quantum Mechanics, Research, Science Fiction, Star Wars

No, "The Force is [not yet] with us Young Skywalker," but it is an interesting application you might soon find on your next gadget purchase, i.e. using photons instead of electrons switching states to carry information.

It’s not lightsaber time, not yet. But a team including theoretical physicists from the National Institute of Standards and Technology (NIST) has taken another step toward building objects out of photons, and the findings* hint that weightless particles of light can be joined into a sort of “molecule” with its own peculiar force.

The findings build on previous research that several team members contributed to before joining NIST. In 2013, collaborators from Harvard, Caltech and MIT found a way to bind two photons together so that one would sit right atop the other, superimposed as they travel. Their experimental demonstration was considered a breakthrough, because no one had ever constructed anything by combining individual photons—inspiring some to imagine that real-life lightsabers were just around the corner.

Now, in a paper forthcoming in Physical Review Letters, the NIST and University of Maryland-based team (with other collaborators) has showed theoretically that by tweaking a few parameters of the binding process, photons could travel side by side, a specific distance from each other. The arrangement is akin to the way that two hydrogen atoms sit next to each other in a hydrogen molecule.

* M.F. Maghrebi, M.J. Gullans, P. Bienias, S. Choi, I. Martin, O. Firstenberg, M.D. Lukin, H.P. Büchler and A. V. Gorshkov. Coulomb Bound States of Strongly Interacting Photons. Physical Review Letters, September 16, 2015.

NIST: Physicists Show ‘Molecules’ Made of Light May Be Possible, Chad Boutin

Now You Don't...

Credit: NSF

Topics: Applied Physics, Optics, Invisibility, Metamaterials, Transformative Optics

Andrea Alù, an engineering professor at the University of Texas at Austin, has an amazing job description: he makes things invisible. Alù is a leading innovator in metamaterials, artificial materials with properties that allow electromagnetic waves to wrap around them. Those include radio waves--creating the possibility of more efficient antennas--and, at a very small scale, even the light waves that our eyes perceive. That light-bending technology could allow for the creation of microscopes with drastically improved performance. For his work, the National Science Foundation presented Alù with its 2015 Alan T. Waterman Award, which recognizes outstanding young researchers.

National Science Foundation: Andrea Alù makes small things invisible--and that could mean big things for technology

Smooth Operator...

Illustration of the programmable photonic circuit. Photons enter from the left, are processed and exit to the right. The connector at the centre top of the circuit is to the external control system. (Courtesy: Jacques Carolan et al./Science).

Topics: Consumer Electronics, Electrical Engineering, Nanotechnology, Optics, Photonics, Quantum Computer, Semiconductor Technology

Note: "Smooth operator" is in the link title of the above photo in the article. No insult or creative infringement to Helen Folasade Adu (the singer Sade) was intended.

A group of physicists in the UK has made a programmable photonic circuit that can be used to carry out any kind of linear optics operation. The researchers say that the device provides experimental proof of a long-standing theory in quantum information, and could help speed the development of photonic quantum computers, as well as establishing whether quantum computers are fundamentally different from their classical counterparts.

The research builds on work carried out back in 1897 by German mathematician Adolf Hurwitz, who showed how a matrix of complex numbers known as a unitary operator can be built up from smaller 2 × 2 matrices. A unitary operator provides a mathematical description of a linear optical circuit. This is any circuit that uses fairly standard optical components – such as mirrors, half-silvered mirrors and phase shifters – to route photons and cause them to interfere with one other. The operator has as many rows as there are output ports in the circuit and as many columns as there are input ports. With only one photon in the circuit, the probability that it travels from a particular input to a particular output is given by the square of the corresponding matrix entry.

Physics World: Physicists build universal optics chip, Edwin Cartlidge

NIST News...

NIST Director Willie E. May
Credit: NIST

Topics: Chemistry, Diversity in Science, Optics, National Institute of Science and Technology, Photonics

Washington, D.C. – On May 4, 2015, the U.S. Senate confirmed Willie E. May as the second Under Secretary of Commerce for Standards and Technology and the 15th director of the National Institute of Standards and Technology (NIST). May has been serving as acting director since June 2014. He has worked at NIST since 1971, leading research activities in chemical and biological measurement science activities prior to serving as associate director for laboratory programs and principal deputy to the NIST director.

“Willie has been a partner and champion in our efforts to strengthen America’s manufacturing sector and promote innovation, key drivers to spurring economic growth, and core pillars of the Department’s ‘Open for Business Agenda.’ In addition to serving as a world-class research institute, NIST has taken the lead on several major Department of Commerce and Obama Administration priorities, including implementing a national network of manufacturing institutes and working with industry and other stakeholders to develop the NIST Cybersecurity Framework,” said U.S. Secretary of Commerce Penny Pritzker.

Among many other awards and honors, May was elected a Fellow of the American Chemical Society in 2011. He has been recognized with the Department of Commerce's Bronze (1981), Silver (1985) and Gold (1992) medals. The National Organization for the Professional Advancement of Black Chemists and Chemical Engineers (NOBCChE) has recognized him with both the Percy Julian Award for outstanding research in organic analytical chemistry and the Henry Hill Award for exemplary work and leadership in the field of chemistry. May received the 2007 Alumnus of the Year Award from the College of Chemical and Life Sciences at the University of Maryland, and in 2010 he was among the first class of inductees into the Knoxville College Alumni Hall of Fame. He was the keynote speaker for the 2002 winter commencement ceremonies for the University of Maryland's College of Life Sciences, and for Wake Forest University's Graduate School of Arts and Sciences commencement exercises in 2012. [1]

* * * * *

The science and technology of light are essential to a multitude of applications that have transformed our society, and there is much promise that optics and photonics will remain at the forefront of the world’s innovations well into this century.

Moreover, the general excitement in and impact of optics and photonics is growing dramatically. This presentation will highlight: (a) past breakthroughs, present advances and potential future growth in the science and technology of light, (b) the convergence of the International Year of Light, the Nobel Prizes based on light and the various U.S. government initiatives in photonics, and (c) the critical nature of metrology to harnessing the exquisite capabilities of high-frequency, coherent light for different industries. This talk is part of an afternoon NIST program celebrating World Metrology Day. [2]

1. Senate Confirms May as 15th NIST Director, Jennifer Huergo
2. Optics and Photonics: Essential for Our World, May 20, 2015

Dr. Patricia Bath...

Image Source: Link belo

Topics: Diaspora, Diversity, Diversity in Science, Inventor, Ophthalmology, Patents, Women in Science

Patricia Era Bath (born November 4, 1942, Harlem, Manhattan, NY) is an American ophthalmologist, inventor and academic. She has broken ground for women and African Americans in a number of areas. Prior to Bath, no woman had served on the staff of the Jules Stein Eye Institute, headed a post-graduate training program in ophthalmology, or been elected to the honorary staff of the UCLA Medical Center (an honor bestowed on her after her retirement). Before Bath, no black person had served as a resident in ophthalmology at New York University and no black woman had ever served on staff as a surgeon at the UCLA Medical Center. Bath is the first African-American woman doctor to receive a patent for a medical purpose. Her Laserphaco Probe is used to treat cataracts. The holder of four patents, she is also the founder of the American Institute for the Prevention of Blindness in Washington, D.C.

Source: Dr. Patricia Bath, Wikipedia

Cooling Light...

Schematic of the Michelson–Sagnac interferometer used in the cooling experiment. Laser light enters from the left and is split into two beams that make their way round a triangular path and create an optical cavity. The mirror to be cooled is the square object that breaks the beams in the middle of the cavity. The output port is at the bottom of diagram where the light encounters a signal-recycling mirror before travelling to a detector (not shown). (Courtesy: Andreas Sawadsky and Roman Schnabel/Leibniz University of Hannover)

Topics: Laser, Modern Physics, Optics, Quantum Computer, Quantum Mechanics

A new technique for cooling a macroscopic object with laser light has been demonstrated by a team of physicists in Germany and Russia. Making clever use of the noise in an optical cavity, which normally heats an object up, the technique could lead to the development of "stable optical springs" that would boost the sensitivity of gravitational-wave detectors. It could also be used to create large quantum-mechanical oscillators for studying the quantum properties of macroscopic objects or to create components for quantum computers.

Physicists already have ways of cooling tiny mirrors by placing them in an optical cavity containing laser light. When the mirror is warm, it vibrates – creating a series of "sidebands" that resonate with light at certain frequencies. The first lower sideband has a frequency equal to the difference between the resonant frequency of the cavity and the vibrational frequency of the mirror. So when a photon at that frequency enters the cavity, it can be absorbed and re-emitted with an extra quantum of vibrational energy. As a result of this "dispersive coupling" process, the mirror cools because energy from it is removed.

Dispersive coupling works best when the bandwidth of the cavity is much smaller than the vibrational frequency of the mirror. This is possible for relatively small mirrors with vibrational frequencies in the hundreds of megahertz. However, for more massive mirrors with vibrational frequencies in the hundreds of kilohertz, optical cavities with sufficiently narrow bandwidths are simply not available.

Physics World:
Physicists reveal new way of cooling large objects with light
Hamish Johnston, editor of physicsworld.com