Photonics and LED Lighting News

Gamma rays reach beyond the limits of light

Researchers have discovered a highly efficient way to produce high energy photon beams. The obtained energy is a billion times higher than the energy of photons in visible light. These high-intensity gamma rays significantly exceed all known limits, and pave the way towards new fundamental studies.

Posted on 20 October 2017 | 12:24 pm

10 years of the trapped rainbow—the revolution of slow light

A decade on from suggesting light can be dramatically slowed - or even stopped - by new materials, Ortwin Hess reviews the progress and applications.

Posted on 20 October 2017 | 10:56 am

Using optical chaos to control the momentum of light

Integrated photonic circuits, which rely on light rather than electrons to move information, promise to revolutionize communications, sensing and data processing. But controlling and moving light poses serious challenges. One major hurdle is that light travels at different speeds and in different phases in different components of an integrated circuit. For light to couple between optical components, it needs to be moving at the same momentum.

Posted on 19 October 2017 | 6:51 pm

Researchers build a 'billion sensors' earthquake observatory with optical fibers

Thousands of miles of buried optical fibers crisscross California's San Francisco Bay Area delivering high-speed internet and HD video to homes and businesses.

Posted on 19 October 2017 | 6:12 pm

Terahertz spectroscopy goes nano

Brown University researchers have demonstrated a way to bring a powerful form of spectroscopy—a technique used to study a wide variety of materials—into the nano-world.

Posted on 19 October 2017 | 6:03 pm

Pushing the limit of thin-film absorption in solar and water-splitting applications

A silicon solar cell harvests the energy of the sun as light travels down through light-absorbent silicon. To reduce weight and cost, solar cells are thin, and while silicon absorbs visible light well, it captures less than half of the light in the near-infrared spectrum, which makes up one-third of the sun's energy. The depth of the material limits absorption. But what if light within the cell could be channeled horizontally so that silicon could absorb its energy along the width of the cell rather than its depth?

Posted on 19 October 2017 | 1:35 pm

Research demonstrates method to alter coherence of light

Brown University researchers have demonstrated for the first time a method of substantially changing the spatial coherence of light.

Posted on 18 October 2017 | 6:00 pm

Scientists reach milestone in 3-D laser writing in bulk silicon

(Phys.org)—It has taken more than 20 years, but researchers have demonstrated for the first time that femtosecond lasers can be used to structurally manipulate bulk silicon for high-precision applications. Since the late '90s, researchers have been using the ultrashort pulses of femtosecond lasers to write into bulk materials with wide band gaps, which are typically insulators. But until now, precise ultrafast laser writing has not been possible for materials with narrow band gaps, such as silicon and other semiconductors.

Posted on 18 October 2017 | 1:30 pm

New 3-D imaging technique for future precision medicine toolbox

For an illness like cancer, doctors often turn to computed tomography (CT) scans for a more definitive diagnosis, based on reconstructing a 3-D organ from multiple 2-D image slices. At the molecular level, such 3-D scans could become an important part of precision medicine: a future of tailoring treatment decisions to each patient's unique cellular features.

Posted on 18 October 2017 | 11:40 am

New imaging approach maps whole-brain changes from Alzheimer's disease in mice

An estimated 5.5 million Americans live with Alzheimer's disease, a type of dementia that causes problems with memory, thinking and behavior. Although treatments can slow the worsening of symptoms, scientists are still working to better understand the neurodegenerative disease so that curative and preventative medicines can be developed. A new imaging system could help speed new drug development by offering a better way to monitor the brain changes indicative of Alzheimer's in mouse models of the disease.

Posted on 17 October 2017 | 4:03 pm

Optical frequency comb offers a convenient way to generate elusive terahertz frequencies 

Optical frequency combs are widely-used, high-precision tools for measuring and detecting different frequencies—a.k.a. colors—of light. Unlike conventional lasers, which emit a single frequency, these lasers emit multiple frequencies simultaneously. The equally spaced frequencies resemble the teeth of a comb. Optical frequency combs are used for everything from measuring the fingerprints of specific molecules to detecting distant exoplanets.

Posted on 17 October 2017 | 12:39 pm

Scientists revisit optical constants of ultrathin gold films

Researchers at MIPT have conducted highly precise measurements of the optical constants of ultrathin gold films with thicknesses ranging from 20 to 200 billionths of a meter in the optical part of the electromagnetic spectrum. Thin gold films are key components of modern micro- and nanoscale optical and optoelectronic devices. The research findings will be in demand among researchers in the field. The paper was published in the journal Optics Express.

Posted on 17 October 2017 | 12:14 pm

A miniature laser-like device for surface plasmons

Researchers at ETH Zurich have developed a miniature device capable of producing laser-like beams of a particular kind of electromagnetic wave called a surface plasmon. Surface plasmons can be focused much more tightly than light waves, making them useful for applications such as sensing.

Posted on 17 October 2017 | 11:39 am

Doubling the power of the world's most intense laser

The most intense laser in the world is about to get a power upgrade with $2 million from the National Science Foundation.

Posted on 17 October 2017 | 11:36 am

Plasma optic combines lasers into superbeam

Since its introduction in the 1977 film "Star Wars," the Death Star has remained one of science fiction's most iconic figures. The image of Alderaan's destruction at the hands of the Death Star's superlaser is burned into the memory of millions of fans.

Posted on 17 October 2017 | 10:45 am

Plasmons in an open box create miniature laser

Scientists at the National Institute of Standards and Technology (NIST) have developed the first miniature laser in which the light is guided along the floor of an open metallic trench. The laser could act as a nanoscale device to sense minute amounts of pollutants and other chemicals in the environment, or detect the surface binding of biomolecules for medical diagnostics.

Posted on 13 October 2017 | 11:50 am

Mantis shrimp-inspired camera enables glimpse into hidden world

By mimicking the eye of the mantis shrimp, Illinois researchers have developed an ultra-sensitive camera capable of sensing both color and polarization. The bioinspired imager can potentially improve early cancer detection and help provide a new understanding of underwater phenomena, the researchers said.

Posted on 13 October 2017 | 6:24 am

Laser cavities take on new shapes and functionalities

Researchers have demonstrated the first laser cavity that can confine and propagate light in any shape imaginable, even pathways with sharp bends and angles. The new cavity, called a topological cavity, could enable laser components to be packed more densely on a chip, leading to higher speed optical communication technologies that can be fabricated in an efficient and scalable manner using photonic integration techniques.

Posted on 12 October 2017 | 6:00 pm

In a first for wearable optics, researchers develop stretchy fiber to capture body motion

The exciting applications of wearable sensors have sparked a tremendous amount of research and business investment in recent years. Sensors attached to the body or integrated into clothing could allow athletes and physical therapists to monitor their progress, provide a more detailed level of motion capture for computer games or animation, help engineers build robots with a lighter touch or form the basis for new types of real-time health monitors.

Posted on 12 October 2017 | 2:00 pm

Researchers implement entanglement swapping with independent sources over 100km optical fiber

A group of scientists led by Prof. Zhang Qiang and Pan Jianwei from the University of Science and Technology of China (USTC) have successfully demonstrated entanglement swapping with two independent sources 12.5 km apart using 103 km optical fiber.

Posted on 12 October 2017 | 9:14 am

53 attoseconds: Research produces shortest light pulse ever developed

Researchers at the University of Central Florida have generated what is being deemed the fastest light pulse ever developed.

Posted on 11 October 2017 | 5:55 pm

A safe optical fiber for delivering light and drugs into the body

A flexible, biodegradable optical fiber that can deliver light into the body for medical applications is the latest work of a collaboration between electrical engineers and biomaterials engineers in Penn State's Materials Research Institute.

Posted on 11 October 2017 | 11:15 am

Electrons surfing on a laser beam

The Large Hadron Collider at CERN in Switzerland, the largest accelerator in the world, has a circumference of around 26 kilometres. Researchers at Friedrich-Alexander Universität Erlangen-Nürnberg (FAU), Germany, are attempting to go to the other extreme by building the world's smallest accelerator—one that fits on a microchip. The research team has now taken another step towards achieving this ambition.

Posted on 11 October 2017 | 10:33 am

Researchers fabricate 3-D silicon structures with a focused infrared laser

Physicist Richard Feynman once gave a lecture titled "There is plenty of room at the bottom." This lecture is often quoted to highlight the successes of modern micro- and nano-fabrication techniques, and the value of available space that comes with advances in miniaturization. In this respect, silicon, the bedrock of modern computers, mobile communications, and photonic devices, has proven to be extremely capable. These advances are usually described in terms of Moore's law. However, modern processors are essentially stacks of planar structures. In this sense, silicon microelectronics and photonics are still 2-D.

Posted on 11 October 2017 | 10:30 am

Spin-current generation gets mid-infrared boost with plasmonic metamaterial

Over the last few years, researchers have demonstrated that light can serve as a spin-current generator, creating currents of angular momentum, in optical nanostructures known as plasmonic absorbers, opening up a new branch of spintronics called opto-spintronics.

Posted on 10 October 2017 | 3:00 pm

Public unwittingly buying dangerous laser pointers, warn scientists

Dangerous laser pointers are being sold to the public which unwittingly believes them to be safe, scientists from the University of Bath have warned.

Posted on 10 October 2017 | 11:22 am

Single 'solitons' promising for optical technologies

Researchers are a step closer to harnessing single pulses of light called solitons, using tiny ring-shaped microresonators, in findings that could aid efforts to develop advanced sensors, high-speed optical communications and research tools.

Posted on 9 October 2017 | 8:46 pm

A zero-index waveguide: Researchers directly observe infinitely long wavelengths for the first time

In 2015, researchers at the Harvard John A. Paulson School of Engineering and Applied Sciences (SEAS) developed the first on-chip metamaterial with a refractive index of zero, meaning that the phase of light could be stretched infinitely long. The metamaterial represented a new method to manipulate light and was an important step forward for integrated photonic circuits, which use light rather than electrons to perform a wide variety of functions.

Posted on 9 October 2017 | 3:00 pm

A dash of gold improves microlasers

Gold. The word brings to mind wedding rings, buried treasure and California in the 1840's. But when gold is reduced to 1/100,000 the size of a human hair, it takes on an entirely new personality.

Posted on 6 October 2017 | 6:02 pm

Asymmetric sound absorption lets in the light

If you've ever lived in an apartment building or stayed in a hotel room, you are probably familiar with the inconvenience of inadequate sound absorption. Acoustic absorption refers to the absorption of sound energy by a material. Whether it's to improve acoustics or to prevent noisy neighbors, sound absorption has multiple applications in engineering and architecture, which can be improved by asymmetric acoustics.

Posted on 6 October 2017 | 5:57 pm