#Migraines triggered by protein deep in the brain It can start with flashing lights, a tingling sensation and a feeling of unease, followed by excruciating pain.
#Echoless light could help send signals through walls and skin IT a call with no response.
and shone light through it. As expected, the light emerging at the other end had become distorted.
They measured the exact degree of distortion and how the profile of the pulse changed on its journey through the fibre.
Finally, they created a light pulse with the exact cross-section needed to counteract the distortion and emerge from the fibre intact and found that it did just that. ven
#4-D laser printing: holograms and beyond Novel tech that manipulates light has applications beyond holograms,
from studying alien worlds to making cellphones more energy efficient In 2010, Michael Escuti received funding from the National Science Foundation (NSF) to study
and make novel hologram technologies. He created a tool that did much more. The technology is a new way to manipulate light,
with applications from studying alien worlds to making cellphones more energy efficient.""Not long after we received the NSF funding,
we were able to create something called the direct-write laser scanner (DWLS), which allows us to create nearly perfect geometric phase holograms,
"says Escuti, an engineer at North carolina State university.""They look like flat, semi-translucent plates, but they give us unprecedented control over the behavior of light.
"To make geometric phase holograms, the DWLS"prints"using an ultraviolet laser on a super-thin film--only about 50 nanometers thick.
The film is made of a photoreactive polymer that responds to both the intensity and the polarization of the light.
When the DWLS is done printing, a much thicker layer of liquid crystal is applied, amplifying the pattern on the underlying thin film.
you have to understand that it doesn't have an inkjet--it prints light, and it prints in four dimensions.
And it can also vary the intensity of the light. But, crucially, it is also capable of controlling the orientation angle of the linear polarization of the light.
Think of a beam of light as a wiggling wave, which vibrates in a perpendicular direction relative to the direction it is traveling.
Control of the orientation angle of the linear polarization of light means control of the direction that the wave is wiggling.
And this polarization angle can be manipulated without changing the angle the light is traveling. In other words, a laser can be pointed directly at an object and
while the polarization angle may change, the direction of the laser beam relative to the object stays the same.
One reason the DWLS is unique is that it produces geometric phase holograms that are smoothly varying
and create complex patterns seamlessly--there are no dividing lines or pixels--unless they are desired actually. This prevents light from"leaking"out of the pattern
and corrupting the signal coming out of the hologram. From the lab to the stars After creating the DWLS,
Escuti looked for potential applications. And that search brought him to a team of astronomers at Leiden University
in theory, can use light to help them unravel the mysteries of the universe. But these theoretical designs were hampered often by the limits of technology."
and instrument designs that could make better use of the light collected by telescopes, "Escuti says."
if we could make holograms with specific characteristics that had previously been technologically impossible. And we could."
his team has provided the astronomers with geometric phase holograms that they have used build advanced coronagraphs--telescopes that can see things close to stars--to study exoplanets beyond our solar system."
"They wanted to redistribute the blazing light of the halo around a star, so that the faint light coming from a planet orbiting that star can be observed with better contrast
--and then analyze the planet's light to learn about its composition and other characteristics,
"With these components and techniques, we have for the first time in perhaps many decades fundamentally expanded the astronomer's toolkit for manipulating light from astronomical sources,
Down to earth applications In addition to astronomy, the DWLS has found use in creating geometric phase holograms for use in mobile displays, holographic imaging,
and designed in partnership with Snik for the International Year of Light. Escuti is continuing to work on new applications with direct support from the National Science Foundation and the Jet propulsion laboratory
#Mini X-ray source driven by laser light alone A new method to produce three-dimensional images of soft tissue structures in organisms using laser-generated X-rays
and the Technische Universität München (TUM) have captured three-dimensional images of ultrafine structures in the body of a living organism for the first time with the help of laser-generated X-rays.
Using light-generated radiation combined with phase-contrast X-ray tomography, the scientists visualized ultrafine details of a fly measuring just a few millimeters.
By contrast, the laser-driven system in combination with phase-contrast X-ray tomography only requires a university laboratory to view soft tissues.
The paper states,-rays radiated by relativistic electrons driven by well-controlled high-power lasers offer a promising route to a proliferation of this powerful imaging technology.
A laser-driven plasma wave accelerates and wiggles electrons, giving rise to a brilliant kev X-ray emission. his so-called betatron radiation is emitted in a collimated beam with excellent spatial coherence and remarkable spectral stability.
Our results suggest that laser-based X-ray technology offers the potential for filling the large performance gap between synchrotron-and current X-ray tube-based sources.
scientists coupled their technique for generating X-rays from laser pulses with phase-contrast X-ray tomography to visualize tissues in organisms.
The X-rays required were generated by electrons that were accelerated to nearly the speed of light over a distance of approximately one centimeter by laser pulses lasting around 25fs.
The laser pulses have a power of approximately 80tw. By way of comparison: an atomic power plant generates 1, 500mw.
First, the laser pulse ploughs through a plasma consisting of positively charged atomic cores and their electrons like a ship through water, producing a wake of oscillating electrons.
Each light pulse generates an X-ray pulse. The X-rays generated have special properties: a wavelength of approximately 0. 1nm,
which corresponds to a duration of only about 5fs, and are spatially coherent, i e. they appear to come from a point source.
For the first time, the researchers combined their laser-driven X-rays with a phase-contrast imaging method developed by a team headed by Prof.
This laser-based imaging technique enables creation of three-dimensional images of objects. After each X-ray pulse, meaning after each frame,
however, researchers must shorten the wavelength of the X-rays even further in order to penetrate thicker tissue layers r
a laser is used to induce fluorescence. This detection mode is not only highly sensitive, but it can also generate a wide range of information about the type and behavior of the marked biomolecules.
#Activated glass chip creates widest wavelength range Scientists from University of Twente research institute MESA+(Twente,
strengthening, and modulating light beams. The MESA+chip can create a very wide light spectrum spanning blue to infrared (470 to 2130nm.
With a broader spectrum, meaning a larger variety of colors in the light, and a large number of light channels set next to each other,
Creating such a spectrum with many individual lasers is technically complex, expensive and less precise than from an integrated source.
The MESA+researchers have for a long time been looking for methods to generate the broadest possible light spectrum on a chip.
what they are calling he broadest light spectrum ever The chip achieves a bandwidth of 495thz,
the researchers shone laser light into a waveguide, made of silicon nitride, a glass-like material, embedded in regular glass (silicon dioxide).
The shape and construction of the waveguide ensures that the laser light generates new wavelengths as it passes through;
The research was performed by scientists from the Laser Physics and Nonlinear Optics department of UT research institute MESA+(within the strategic research direction Applied Nanophotonics) in collaboration with the Westfälische Wilhelms-Universität (WWU) Münster and the companies Lionix and Xio Photonics.
The research was supported financially by the Technology Foundation STW and recently published in Optics Express.
When pumped at a center wavelength of 1064nm with pulses of 115 fs duration, the generated spectrum ranges from the visible blue range (470 nm) to the infrared (2130 nm)
and Sio2, appears to be highly attractive for applications such as for self-referencing optical frequency combs on a chip or widely tunable light sources for label-free microscopy and imaging in life sciences. m
The work is described in the latest issue of Nature Photonics. While optical fibers have long been used for the transmission of data with light, inside a computer
data are processed almost invariably and stored electronically. But electronic exchange of data between processors and the memory limits the speed of modern computers.
and from amorphous to crystalline (data-erasing) is initiated by ultrashort light pulses. For reading back the data, weak light pulses are used.
The scientists conclude that permanent all-optical on-chip memories could onsiderably increase future performance of computers while reducing their energy consumption.
The Nature Photonics paper states, y using optical near-field effects, we realize bit storage of up to eight levels in a single device that readily switches between intermediate states.
We show that individual memory elements can be addressed using a wavelength-multiplexing scheme. Our multilevel, multi-bit devices provide a pathway towards eliminating the Von neumann bottleneck
and Applied sciences (SEAS) say they have made it easier to manipulate light at the nanoscale. They have developed the first on-chip metamaterial with a refractive index of zero,
meaning that the phase of light can travel infinitely fast. The new metamaterial was developed in the lab of Eric Mazur, the Balkanski Professor of Physics and Applied Physics and Area Dean for Applied Physics AT SEAS,
and is described in the journal Nature Photonics. The metamaterial consists of low-aspect-ratio silicon pillar arrays embedded in a polymer matrix and clad by gold films.
and can efficiently couple to photonic integrated circuits and other optical elements. ight doesn typically like to be squeezed
or manipulated but this metamaterial permits us to manipulate light from one chip to another, to squeeze,
measured by how fast the crests of a wavelength move, known as phase velocity. This speed of light increases or decreases depending on the material it passes through.
When light passes through water, for example, its phase velocity is reduced as its wavelengths are squeezed together.
Once it exits the water, its phase velocity increases again as its wavelength elongates. How much the crests of a light wave slow down in a material is expressed by the index of refraction;
RI=zero The Nature Photonics paper explains what happens when a material refractive index is reduced to zero:"
or all troughs stretching out in infinitely long wavelengths. The crests and troughs oscillate only as a variable of time, not space."
"This uniform phase allows the light to be stretched or squashed, twisted or turned, without losing energy.
as incoming waves of light are effectively spread out and infinitely long, enabling even distant particles to be entangled
#Laser array on silicon promises new level of photonic integration Scientists in Belgium are claiming a breakthrough advance for integrated photonics by fabricating an array of laser diodes on a large silicon wafer typical
In a paper published in the latest issue of Nature Photonics the IMEC and University of Ghent team describes the development as the irst highly scalable monolithic solutionto a longstanding problem:
integrating laser sources on a silicon platform. And while the laser structures have so far only been demonstrated with optical pumping,
the team led by Ghent Dries Van Thourhout suggests that electrical injection-a necessity for true photonic integration-could be achieved readily with the incorporation of a suitable blend of narrow-bandgap semiconductor material in the future.
Van Thourhout and colleagues made an array of distributed feedback (DFB) indium phosphide (Inp) lasers on a 300 mm diameter wafer,
accurate control on the distribution of lasing wavelengths in the array was demonstrated by modifying the grating parameters.
That ability to carefully control the laser wavelengths suggests that the devices ought to be compatible with wavelength division multiplexing (WDM) schemes that are used widely in today optical communications systems.
Add to that a very high-yielding process (the team claims that at least 98 per cent of more than 200 devices characterized so far have showed laser operation)
or 1550 nm optical communications wavelength while dealing with the problems caused by the major crystal lattice mismatch with silicon.
Learning from recent attempts to combine III-V and silicon materials in Finfet electronic devices, the Belgian team grew their laser structures directly onto a standard silicon wafer.
we fabricated DFB lasers exhibiting robust single-mode operation. Thin buffer layer crucial The usual way to overcome the lattice mismatch between silicon
The result was an Inp-on-silicon array of DFB lasers emitting at between 915 nm
YAG laser provided by Ekspla. Although that is not the ideal lasing wavelength for silicon waveguides,
and electrical pumping must also be achieved for real applications, Van Thourhout and colleagues outlined how these challenges could be met. he in-plane laser configuration employed makes it straightforward to adopt well-studied electrical injection schemes,
they wrote, adding that the Inp-on-silicon material platform developed could act as a irtualinp substrate upon
That approach would allow deposition of the compound semiconductor materials needed to red-shift the lasing wavelength into the telecoms realm at 1300 nm.
And because the extremely thin buffer layer allows light to be emitted in the plane of the wafer
it is even possible to envisage butt-coupling the lasers to optical waveguides defined at the same level. n addition,
direct contact of the III lasers with silicon-on-insulator (SOI) wafers will improve the thermal dissipation of the device,
on-chip lasers that could be produced using the approach, concluding that: n particular, for on-chip optical interconnects, the demonstrated monolithic laser array,
together with the WDM technology, may finally pave the way to terascale computing. Photonic integrated circuits (PICS) based on the technology could dramatically change the architecture of fiber-optic transceivers used in data center optical interconnects, by pushing down the cost of chip-level data transfer between logic and memory devices.
That would in turn enable a radical scaling of a data center capacity, while simultaneously reducing increasingly colossal power demands with higher-efficiency data transfer.
but by implementing new technologies like silicon photonics this total could be cut by at least 10 per cent.
Importantly, the laser integration work was carried out in IMEC 300mm CMOS pilot line facility, providing a path to large volume manufacturing
IMEC says that efforts are focused now on growing the more complex semiconductor layer stacks needed for electrical injection of the lasers and emission in the 1300 nm wavelength range d
"Luminescent materials are shown under UV LIGHT, emitting different colors that can be altered by environmental conditions. Courtesy of Tara Fadenrecht/MIT.
and lights up whenever any of the cells are activated. Observing a mouse spinal cord through a microscope
#Microscale 3d'Bar codes'Readable with Lasers Microscale indentations that can be read by laser scanners serve as 3d bar codes that could help distinguish between genuine and counterfeit goods. A prototype device for creating the bar codes has been developed by Sofmat Ltd
The system has been verified in the laboratory using a white light interferometer and a laser-scanning confocal microscope to characterize the surface of the coded product
and ensure the code is reproduced accurately.""A 3d bar code allows much more complexity than existing anticounterfeit systems,
"A laser scanner is in development that will be able to read the code and wirelessly transmit the result to mobile devices.
which detect strain by measuring shifts in the wavelength of light propagating through optical fiber. Conventional pressure or force sensors are problematic
allowing light to escape. By measuring the loss of light, the researchers are able to calculate strain or other deformations.
Industrial robots, working in a controlled environment where people aren't present, are capable of extremely precise manipulation with only limited sensors.
#UV Catheter Plugs Holes in Hearts With help from UV LIGHT, a new catheter device could provide a way to repair defects in hearts and other organs without surgery.
The clinician then deploys the patch and turns on the catheter's UV LIGHT. The light reflects off of the balloon's shiny interior
and activates the patch's adhesive coating. As the glue cures, pressure from the balloons secures the patch it in place.
and then activate it using UV LIGHT, all within a matter of five minutes and in an atraumatic way that doesn't require a separate incision."
Under development by the University of Washington and Microsoft Research, the Hypercam uses both visible and near-infrared light to peer beneath the surface
Hypercam illuminates a scene with 17 wavelengths. Software analyzes the resulting images to present the user with the most useful information."
"One challenge is that the technology doesn't work particularly well in bright light, Goel said.
#Light-Sheet Microscope Pushes Resolution Limits With resolution seven times greater than conventional light-sheet microscopes, an advanced device can capture cell-level 3d images across entire small organisms.
Called Isoview, it's the first light microscope capable of imaging large, nontransparent specimens at subsecond temporal resolution and subcellular spatial resolution in all dimensions, according to group leader Philipp Keller.
From each side, an objective produces a thin beam of light that sweeps the sample from top to bottom.
when they are exposed to near-infrared light. Tests at this early stage are designed to make sure that the paint works as it's supposed to,
so the surgeons had to remove a piece of the tissue before shining a light on it.
Pete Jameson, chief operating officer at ODG, points out that the company R-6 glasses, commercially available for just under $5, 000, have an ambient light sensor and swappable photochromic shields for handling glare."
the team also applied UV LIGHT to disinfect some of the water as it passed through the system.
Because of the newfound clarity of the material, it could also work in lasers, protecting the components inside a directed energy weapon from the ravages of sea or sand while still letting the laser shine through.
Now that the Navy has developed a reliable means of manufacturing the material, the next step is handing it off to industry and seeing
and at 350 grams should be light enough that it's not too distracting to players s
AVERT's deployment unit can scan locations of a targeted vehicle using laser-based LIDAR,
it rendered the tape invisible in particular wavelengths of light. The researchers presented their work this week at the meeting of the American Chemical Society in Denver.
which wavelengths of light it reflects. An application of this material could be useful for certain types of camouflage during the day,
He and his team are tweaking the material to work at more varied wavelengths of light.
which New Scientist posted on Youtube is more akin to CNN holograms than Twister; there are no flying cows,
#Boeing Just Patented A Force field Made Of Lasers So, Boeing just patented a force field. Technically, the patent is for a ethod and system for shockwave attenuation via electromagnetic arc,
Next, the signal from the sensor triggers a laser (or a blast of electricity or microwave energy) that heats up a section of air or water
The liquid metal could be used to build self contained pumps that don't require outside power or batteries, saving on weight and complexity for items like night vision and laser cooling pumps.
or changes in how light is reflectederfect for maneuvering drones through small spaces with lots of obstacles.
It made of three photodetectors with a lens on top. With the combination of data from the photodetectors,
which are arranged in a triangular configuration, the device can determine the speed and direction in its view,
Since they have developed already the algorithms and design of the photosensor, the researchers plan to configure several artificial eyes on one drone to create a more sophisticated visual system,
Two previous prototype made by NIII used either near-infrared light or reflectors to fool the cameras into not seeing a face,
Instead of the electrically powered near-infrared lights of the earlier visors, these glasses use an unspecified novel material to absorb
Previous attempts to hide faces from computers have resorted to eye-catching makeup or dangling lights from baseball caps.
But a quick laser scan could prove a product origin, which the engineers say could track
The FDA has designed also a device that uses UV LIGHT to scan pills and their packaging.
For workers, there a blue screen option where it will lower the amount of blue light emitted from the screen to help protect a user lens.
a technique using electrons (instead of light or the eyes) to see the characteristics of a sample,
Scientists at the Max Planck Institute for Solid State Research in Stuttgart and from LMU Munich have created now a material that uses light to produce the versatile energy source hydrogen from water.
Migrating charge carriers Photocatalysts must contain charge carriers that can be excited using visible light so that they can move relatively freely
When irradiated with visible light, the mixture starts producing hydrogen. The scientists were thrilled not only that the
which also includes an LED light source, power supply, control unit, optical system, and image sensor, cost less than $3, 000 to construct.
#Researchers transform slow emitters into fast light sources Researchers from Brown Univ, . in collaboration with colleagues from Harvard, have developed a new way to control light from phosphorescent emitters at very high speeds.
The technique provides a new approach to modulation that could be useful in all kinds of silicon-based nanoscale devices,
a process that often involves flipping the light on and off to encode information. Because of their slow lifetimes, phosphors have traditionally been a nonstarter for applications that require high-speed modulation.
"Instead of changing how much light is coming out, which can only be done slowly in phosphor emitters,
we came up with a system that changes another quality of that light, namely the color or spectrum of light emission,
Prototype on-chip networks have used semiconductor lasers as light emitters. They can modulate very quickly,
What's more, semiconductor lasers are not particularly efficient. They produce a lot of heat along with light
which is a problem on a silicon chip. Erbium and other phosphors, on the other hand, can be deposited directly on silicon, making fabrication easier.
In this initial experiment, the researchers used a laser to zap the VO2 and cause it to change phase.
A faster means of changing the VO2 phase--perhaps using electricity instead of a laser--could make the system much faster still.
and industrial researchers working on optoelectronics and nanophotonics, "the researchers write e
#Experimental treatment regimen effective against HIV PROTEASE inhibitors are a class of antiviral drugs that are used commonly to treat HIV, the virus that causes AIDS.
Specifically, the research team used the surface waves of Linbo3 to listen to how the illumination of Linbo3 by laser light changes the electric properties of Mos2. he tone at
and infer how much current the laser light allowed to flow in the Mos2. We also fabricated transistor structures onto the Mos2 films
director of the Wireless@MIT center. ou could also imagine it being used to operate your lights and TVS,
director of the Wireless@MIT center. ou could also imagine it being used to operate your lights and TVS,
After creating the tattoo-like designs on a computer, a laser cutter traces out the design
while testing a laser-based measurement technique that they recently developed to look for what is called multipolar order. o understand multipolar order,
all of the light that you see reflected from the object is at that frequency. When you shine a red laser pointer at a wall, for example,
your eye detects red light.?However, for all materials, there is a tiny amount of light bouncing off at integer multiples of the incoming frequency.
So with the red laser pointer, there will also be some blue light bouncing off of the wall.
You just do not see it because it is such a small percentage of the total light.
their idea was that the optical harmonic response of a crystal could serve as a fingerprint of multipolar order. e found that light reflected at the second harmonic frequency revealed a set of symmetries completely different from those of the known crystal structure,
whereas this effect was completely absent for light reflected at the fundamental frequency. This is a very clear fingerprint of a specific type of multipolar order,
and his colleagues uses high-amplitude sound waves to generate an acoustic hologram which can pick up
Here we individually control dozens of loudspeakers to tell us an optimal solution to generate an acoustic hologram that can manipulate multiple objects in real-time without contact,
The current study also sheds new light on the transmission to children of LGDS that are carried by parents who harbor them but
Researchers bioengineer cells to make them sensitive to specific frequencies of light, then use light pulses to switch cells,
or the processes being carried on inside them, on and off. For this experiment the team members engineered a line of neurons to simulate a portion of the human nervous system.
They translated the electronic pressure signals from the artificial skin into light pulses which activated the neurons,
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