Optical fibers are hair-like threads of glass used to guide light. Fibers of exceptional purity have proved an excellent way of sending information over long distances and are the foundation of modern telecommunication systems. Transmission relies on what's called total internal reflection, wherein the light propagates by effectively bouncing back and forth off of the fiber's internal surface.
Researchers at the Kastler Brossel Laboratory in Paris have managed to store light that...
Computers that function like the human brain could soon become a reality thanks to new research...
Univ. of Wisconsin-Madison geoscientists and engineers are working with industry partners and...
A new way to process fiber optic signals has been demonstrated by Univ. College London researchers, which could double the distance at which data travels error-free through transatlantic submarine cables. The new method has the potential to reduce the costs of long-distance optical fiber communications as signals wouldn’t need to be electronically boosted on their journey.
The idea of computing systems based on controlling atomic spins just got a boost from new research performed at MIT and Brookhaven National Laboratory. By constructing tiny "mirrors" to trap light around impurity atoms in diamond crystals, the team dramatically increased the efficiency with which photons transmit information about those atoms' electronic spin states, which can be used to store quantum information.
Researchers from the University of Southampton have revealed a breakthrough in optical fiber communications. Academics have collaborated to develop an approach that enables direct modulation of laser currents to be used to generate highly advanced modulation format signals.
Projecting images on curved screens poses a dilemma. The sharper the image, the darker it is, even when using lasers and scanning mirrors. A novel optical approach involving the use of an array of microprojectors now brings brightness and sharpness together for the first time on screens of any curvature. It also allows an increase in projection rates by about 10,000 times.
Action-packed science-fiction movies often feature colorful laser bolts. But what would a real laser missile look like during flight, if we could only make it out? How would it illuminate its surroundings? The answers lie in a film made by researchers in Poland who have captured the passage of an ultrashort laser pulse through the air.
Laser physicists in Australia have built a tractor beam that can repel and attract objects, using a hollow laser beam that is bright around the edges and dark in its center. It is the first long-distance optical tractor beam and has moved particles one-fifth of a millimeter in diameter a distance of up to 20 cm, around 100 times further than previous experiments.
Duke Univ. researchers have made fluorescent molecules emit photons of light 1,000 times faster than normal, setting a speed record and making an important step toward realizing superfast light emitting diodes (LEDs) and quantum cryptography. This finding could help make LED technology, which earned a Nobel Prize this year, suitable for use as a light source in light-based telecommunications.
Spectroscopic chemical sensing has great promise, but current technologies lack sensitivity and broad spectral coverage. DARPA’s Spectral Combs from UV to THz (SCOUT) program aims to overcome these limitations. The goal is to develop chip-sized, optical frequency combs that accurately identify even tiny traces of dangerous biological and chemical substances several football fields away, DARPA is now soliciting proposals for a solution.
Scientists at EPFL in Switzerland have designed a first-ever experiment for demonstrating quantum entanglement in the macroscopic realm. Unlike other such proposals, the experiment is relatively easy to set up and run with existing semiconductor devices.
At the Vienna Univ. of Technology gold nanoparticles have been coupled to a glass fiber. The particles emit light into the fiber in such a way that it does not travel in both directions, as one would expect. Instead, the light can be directed either to the left or to the right. This became possible by employing the spin-orbit coupling of light, creating a new kind of optical switch that has the potential to revolutionize nanophotonics.
The world’s fiber-optic network spans more than 550,000 miles of undersea cable that transmits Email, Websites and other packets of data between continents, all at the speed of light. A rip or tangle in any part of this network can significantly slow telecommunications around the world. Now, engineers have developed a method that predicts the pattern of coils and tangles that a cable may form when deployed onto a rigid surface.
A rip or tangle in any part of world’s 550,000-mile fiber-optic network can significantly slow telecommunications around the world. Now engineers have developed a method that predicts the pattern of coils and tangles that a cable may form when deployed onto a rigid surface. The research combined laboratory experiments with custom-designed cables, computer-graphics technology used to animate hair in movies, and theoretical analyses.
Commercial devices capable of encrypting information in unbreakable codes exist today, thanks to recent quantum optics advances, especially the generation of photon pairs. Now, an international team is introducing a new method to achieve a different type of photon pair source that fits into the tiny space of a computer chip. The team’s method generates “mixed up” photon pairs from devices that are less than one square millimeter in area.
Confined photons have many potential applications, such as efficient miniature lasers, on-chip information storage, or tiny sensors on pharmaceuticals. Making a structure that can capture photons is difficult, but scientists in the Netherlands have recently devised a new type of resonant cavity inside a photonic crystal that imprisons light in all three dimensions.
Using an optical microstructure and gold nanoparticles, scientists have amplified the interaction of light with DNA to the extent that they can now track interactions between individual DNA molecule segments. In doing so, they have approached the limits of what is physically possible. This optical biosensor for single unlabelled molecules could also be a breakthrough in the development of biochips:
Optical circuits use light instead of electricity, making them faster and more energy-efficient than electrical systems. Scientists in Switzerland have now developed a silicon-based photonic crystal nanocavity to be used as a first building-block for photonic “transistors”. The new device requires record low energy to operate.
The invention of fiber optics revolutionized the way we share information, allowing us to transmit data at volumes and speeds we’d only previously dreamed of. Now, electrical engineering researchers at the Univ. of Alberta are breaking another barrier, designing nano-optical cables small enough to replace the copper wiring on computer chips.
To make a better optical fiber for transmitting laser beams, the first idea that comes to mind is probably not a nice long hydrogen bath. And yet, scientists have known for years that hydrogen can alter the performance of optical fibers, which are often used to transmit or even generate laser light in optical devices. Researchers at NIST have put this hydrogen “cure” to practical use.
With the help of ultracold quantum gas, physicists have achieved a 20-fold amplification of single-photon signals, a step that could aid all-optical data processing efforts. The breakthrough was made with the invention of a new type of optical transistor build from a cloud of rubidium atoms, held just above absolute zero, that is transparent to certain wavelengths of light.
Scientists in the U.K. recently published work that describes how graphene can be wrapped around a silicon wire, or waveguide, and modify the transmission of light through it. These waveguide loops, called “racetrack resonators” because of their shape, could help form a device architecture that would make graphene biochemical sensors a reality.
A new home-grown instrument based on bundles of optical fibers is giving Australian astronomers the first “Google street view” of the cosmos—incredibly detailed views of huge numbers of galaxies. Developed by researchers at the Univ. of Sydney and the Australian Astronomical Observatory, the optical-fiber bundles can sample the light from up to 60 parts of a galaxy, for a dozen galaxies at a time.
Scientists in Belgium have recently fabricated the world’s first randomly deformable optical waveguide. This innovative optical link remains functional for bending radii down to 7 mm, and can be stretched to more than a third of its length. A link like this can be used to interconnect optical components within a stretchable system, just like stretchable electrical interconnections.
Nonlinear optical materials are widely used in laser systems, but they require high light intensity and long propagation to be effective. A team in Germany and Texas has designed a new 400-nm thick nonlinear mirror that delivers frequency-doubled output using input light intensity as small as that of a laser pointer. Compared to traditional nonlinear materials, the new option offers a million times increase in nonlinear optical response.
By fusing together the concepts of active fiber sensors and high-temperature fiber sensors, a team of researchers at the Univ. of Pittsburgh has created an all-optical high-temperature sensor for gas flow measurements that operates at record-setting temperatures above 800 C. The new technology should be ideal for use in deep drilling operations, nuclear reactor cores and outer space.
A team of scientists in Japan and New Zealand have combined lasers, nanotechnology, and neuroscience to develop a new, versatile drug delivery system. The precise timing of a femtosecond laser is used to release dopamine, a neurochemical, that is dysfunctional in Parkinson’s Disease in a controlled and repeatable manner that mimics the natural dynamic release mechanism.
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