in light of revelations by Edward Snowden that U s. agencies spied upon people in other nations,
NG-PON2 transmits the data using certain wavelengths of light that can handle 10 Gbps of capacity each, according to a company release.
and mobile phones, Gan has efficient light emission capability, something silicon cannot duplicate. But silicon remains the defacto material of choice semidconductors
An emerging class of robotic technology uses UV LIGHT to fuse the DNA of viruses and bacteria and prevent them from reproducing,
TRU-D's system analyzes the variables of the room and floods the space (both line-of-site and shadowed spaces) with the proper dose of UV LIGHT energy.
but the light is generally colder than the warm glow of traditional bulbs. Plus most of these lights are made with rare earth elements that are increasingly in demand for use in almost all other high-tech devices
thus adding to the cost of the technology. Jing Li's research team set out to solve the issues of material sources and pricing.
Rather than the light used in a traditional microscope this technique uses focused beams of electrons to illuminate a sample and form images with atomic resolution.
Li and Phillips are developing a new laser-based technology known as the green astro-comb for use with the radial velocity method
Better Precision with a Laserthe radial velocity method works by measuring how exoplanet gravity changes the light emitted from its star.
The star speeds up slightly as it approaches Earth with each light wave taking a fraction of a second less time to arrive than the wave before it.
The astro-comb works by injecting 8000 lines of laser light into the spectrograph. They hit the same pixels as starlight of the same wavelength.
This creates a comb-like set of lines that lets us map the spectrograph down to 1/10000 of a pixel.
I can tell you the precise wavelength Phillips explained. By calibrating the spectrograph this way we can take into account very small changes in temperature or humidity that affect the performance of the spectrograph.
but it only worked with infrared and blue light. Their new version of the astro-comb lets astronomers measure green light
--which is better for finding exoplanets. The stars we look at are brightest in the green visible range
since the researchers needed to convert red laser light to green frequencies. They did it by making small fibers that convert one color of light to another.
Red light goes in and green light comes out Phillips said. Even though I see it every day and understand the physics it looks like magic.
The researchers plan to test the green astro-comb by pointing it at our sun analyzing its spectrum to see
if they can find Venus and rediscover its characteristic period of revolution its size its mass and its composition.
Sagittarius A is visible at radio infrared and X-ray wavelengths. This massive black hole--which contains 4 million solar masses--does not emit radiation
The wavelengths that make Sagittarius A*visible are scattered by interstellar gas along the line of sight in the same way that light is scattered by fog On earth.
While no scientific team has been able to produce a complete image of the black hole's emission astronomers have drawn inferences about scattering properties from observations at longer wavelengths.
We're also interested in looking at shorter wavelengths where we think the emission region may be smaller
Brighter, new energy saving flat panel lights based on carbon nanotubes Even as the 2014 Nobel prize in Physics has enshrined light emitting diodes (LEDS) as the single most significant and disruptive energy-efficient lighting solution of today scientists
Scientists from Tohoku University in Japan have developed a new type of energy-efficient flat light source based on carbon nanotubes with very low power consumption of around 0. 1 Watt for every hour's operation
or cathode and scratched the surface with sandpaper to form a light panel capable of producing a large stable and homogenous emission current with low energy consumption.
Brightness efficiency tells people how much light is being produced by a lighting source when consuming a unit amount of electric power
Although the device has a diode-like structure its light-emitting system is not based on a diode system
Field emission electron sources catch scientists'attention due to its ability to provide intense electron beams that are about a thousand times denser than conventional thermionic cathode (like filaments in an incandescent light bulb.
Many researchers have attempted to construct light sources with carbon nanotubes as field emitter Shimoi said. But nobody has developed an equivalent and simpler lighting device.
It also sheds new light on how immune systems in organisms have evolved. The study Self-association of an Insect Beta-13-Glucan Recognition Protein Upon Binding Laminarin Stimulates Prophenoloxidase Activation as an Innate Immune response was published recently in the Journal of Biological Chemistry.
The Vale team used the Suntag to greatly amplify the light-emitting signal from the green fluorescent protein commonly used by researchers to label molecules within cells.
CRISPR with Suntag Already Is Shedding Light on Cancer and Normal Developmentcrispr--an acronym for clustered regularly interspaced short palindromic repeats--is a natural system that bacteria use to defend themselves against viruses. The basis for CRISPR applications in the lab is a protein from this system called Cas9
#Revving up fluorescence for superfast LEDS Duke university researchers have made fluorescent molecules emit photons of light 1000 times faster than normal--setting a speed record
This year's Nobel prize in physics was awarded for the discovery of how to make blue LEDS allowing everything from more efficient light bulbs to video screens.
and off has limited their use as a light source in light-based telecommunications. In an LED atoms can be forced to emit roughly 10 million photons in the blink of an eye.
To make future light-based communications using LEDS practical researchers must get photon-emitting materials up to speed.
The results appear online October 12 in Nature Photonics. One of the applications we're targeting with this research is said ultrafast LEDS Maiken Mikkelsen an assistant professor of electrical and computer engineering and physics at Duke.
and trapped light between them greatly increasing the light's intensity. When fluorescent molecules are placed near intensified light the molecules emit photons at a faster rate through an effect called Purcell enhancement.
#Getting sharp images from dull detectors Observing the quantum behavior of light is a big part of Alan Migdall's research at the Joint Quantum Institute.
it is normally necessary to use a beam of coherent light, light for which knowing the phase
however, Migdall and his JQI colleagues perform an experiment using incoherent light, where the light is a jumble of waves.
And they use what Migdall calls"stupid"detectors that, when counting the number of photons in a light pulse,
can really only count up to zero, as anything more than zero befuddles these detectors and is considered as number that is known only to be more than zero.
using incoherent light (with a wavelength of 800 nm) sent through a double-slit baffle,
which sub-wavelength interference (to be defined below) has been pushed using thermal light and small-photon-number light detection.
The physicists were surprised that they could so easily obtain such a sharp interference effect using standard light detectors.
The importance of achieving sub-wavelength imaging is underscored by the awarding of the 2014 Nobel prize for chemistry to scientists who had done just that.
Beating the Diffraction Limit When they pass through a hole or past a material edge, light waves will diffract--that is,
a portion of the light will fan out as if the edge were a source of waves itself.
This diffraction will limit the sharpness of any imaging performed by the light. Indeed, this diffraction limitation is one of the traditional features of classical optical science dating back to the mid 19th century.
What this principle says is that in using light with a certain wavelength (denoted by the Greek letter lambda) an object can in general be imaged with a spatial resolution roughly no finer than lambda.
One can improve resolution somewhat by increasing lens diameters, but unless you can switch to light of shorter lambda,
you are stuck with the imaging resolution you've got. And since all the range of available wavelengths for visible light covers only a range of about 2, gaining much resolution by switching wavelengths requires exotic sources and optics.
The advent of quantum optics and the use of"nonclassical light"dodged the diffraction limit.
It did this, in certain special circumstances, by considering light as consisting of particles and using the correlations between those particles The JQI experiment starts out with a laser beam,
but it purposely degrades the coherence of the light by sending it through a moving disk of ground glass.
Thereafter the light waves propagating toward the measuring apparatus downstream originate from a number of places across the profile of the rough disk
and are no longer coordinated in space and time (in contrast to laser light). Experiments more than a decade ago,
however, showed that"thermal"light (not unlike the light emitted haphazardly by an incandescent bulb) made this way,
while incoherent over long times, is coherent for times shorter than some value easily controlled by the speed of the rotating ground glass disk.
Why should the JQI researchers use such thermal light if laser light is available? Because in many measurement environments (such as light coming from astronomical sources) coherent light is not available,
and one would nevertheless like to make sharp imaging or interference patterns. And why use"stupid"detectors?
Because they are cheaper to use. The Experiment In the case of coherent light, a coordinated train of waves approach a baffle with two openings (figure, top.
The light waves passing through will interfere, creating a characteristic pattern as recorded by a detector,
which is moved back and forth to record the arrival of light at various points. The interference of coherent light yields a fixed pattern (right top in the figure.
By contrast, incoherent light waves, when they pass through the slits will also interfere (lower left),
Each of these two portions of light will strike movable detectors which scan across sideways.
That way the two detectors can simultaneously sample the light from virtual positions that can be as close as desired
However, here the time structure of the incoming light pulse becomes important in clarifying the measurement.
But then if we design the light so that its limited coherence time is larger than the recovery time of our stupid detectors,
or equivalently the intensity of the light at various places at the measuring screen, ensures that the set of correlations between the two detectors does result in an interference-like pattern in those correlations.
it could be accomplished by engineering the properties of the light source to accommodate the lack of ability of the detectors
Considering that the incoming light has a wavelength of 800 nm, the pattern is sharper by a factor of 20 or more from
if the diffraction limitation were at work. The fact that the light used is thermal in nature,
and not coherent, makes the achievement more striking. This correlation method is not the same as imaging an object.
But the ease and the degree to which the conventional diffraction resolution limit could be surmounted will certainly encourage a look for specific applications that might take advantage of that remarkable feature e
The ability to mold inorganic nanoparticles out of materials such as gold and silver in precisely designed 3d shapes is a significant breakthrough that has the potential to advance laser technology microscopy solar cells electronics environmental testing disease
Plasmonics involves the control of light at the nanoscale using surface plasmons, which are coordinated waves,
One is that they can measure diffraction at 10 Kelvin(-441°F). Not too many people On earth can do that
and manufacture it more efficiently using an optimized laser process. Transformers convert the standard voltage from the wall outlet into the lower voltages required by electronic devices.
This results in a lower heat development and thus reduces the material's hysteresis loss says Dr. Andreas Wetzig who heads the laser ablation
Laser processing has long become established as the preferred method for this type of heat treatment.
While the steel sheet measuring around one meter in width moves forward at a rate of more than 100 meters per minute a focused laser beam travels at very high speed (approximately 200 meters per second) from side to side
We have developed a means of deflecting the laser beam that allows the distance between the paths to be controlled flexibly
which is used to deflect the laser beam. This increases the flexibility of the machining process and allows it to be adapted to specific conditions such as the quality of the raw material and to different production rates.
The main aim of this research is to facilitate the integration of laser processing in existing production environments in order to save time and costs.
In a further effort to reduce hysteresis loss in electrical steel the researchers have started recently working with a new type of solid-state laser:
the fiber laser. The results we have obtained so far are very promising. This type of laser offers better heat absorption characteristics than traditional CO2 lasers says Wetzig.
It cuts hysteresis loss by up to 15 percent compared with the 10 percent normally achieved until now.
The benefits of laser processing in the case of non-grain-oriented electrical steel vary according to the working point of the specific engine or motor.
The second beam channel produces time-resolved measurements of individual spectral lines--adjusted so that the instrument can distinguish between light emitted by te plasma
and that emitted by the sparks. All previous solutions were based on separate time-resolved and space-resolved measurements.
The new photodetector multiplies the dynamic range by 100 resulting in a much faster spectrometer.
The market for spectroscopy equipment is dominated by German manufacturers says the scientist. Our new sensor which was developed in Germany
Using Light to Watch HIV Dance In the Science study, Dr. Blanchard worked with Dr. Walther Mothes, a HIV specialist at the Yale university School of medicine,
#How metallic alloys reorganize during microscale laser melting processes: Elements of successful connections High-power lasers that can selectively cut
and join metallic products are becoming increasingly important in today's manufacturing industry. Now, Yingchun Guan from the A*STAR Singapore Institute of Manufacturing Technology and her co-workers have developed a technique that reveals exactly how molten elements vaporize
and move about inside a laser-generated surface'plume'1--findings that can advance additive manufacturing techniques used to print three-dimensional (3d) objects.
Recently, the A*STAR team demonstrated that laser surface melting of these alloys enhances their corrosion resistance as a result of a notable enhancement in the surface concentration of aluminum.
however, to make the link between the initial alloy composition and the final product after laser processing,
as many complex interactions occur in the cloudlike plume of laser-generated vapor particles. Guan and her team designed a new experimental setup that can quantify
which molten alloy elements are ejected into the laser plume. They positioned a thin silicon substrate perpendicular to a Mg-Al-based alloy a few millimeters from the laser firing point.
Laser pulses then generated a plume that deposited onto the silicon surface. When the researchers used a scanning electron microscope (SEM) to examine the deposits,
they saw clear evidence of a phase explosion--a mixture of liquid and vaporized particles thrown out by the laser impact.
These liquid deposits rendered many sections of the silicon wafer unsuitable for quantitative analysis. But by combining the element-identifying capability of the SEM with time-of-flight mass spectrometry,
the population of Al ions rises in the middle of the near-field region close to the laser firing point.
"Our chemical analysis of the transport rates and distribution of vaporized species in the plume offers improved understanding of critical laser processes, including those used in additive manufacturing,
#Laser comb system maps 3-D surfaces remotely for manufacturing, forensics Researchers at the National Institute of Standards and Technology (NIST) have demonstrated a laser-based imaging system that creates high-definition 3d maps of surfaces from as far away as 10.5 meters.
The method may be useful in diverse fields including precision machining and assembly as well as in forensics.
NIST's 3d mapping system combines a form of laser detection and ranging (LADAR) which is sensitive enough to detect weak reflected light with the ranging accuracy made possible by frequency combs as previously demonstrated at NIST.
The frequency comb a tool for precisely measuring different frequencies of light is used to continuously calibrate the laser in the imaging system.
Operating with laser power of just 9 milliwatts --which is safe for the eyes at the instrument's infrared wavelength--NIST's 3d mapping system scans a target object point by point across a grid measuring the distance to each point.
The system uses the distance data to make a 3d image of about 1 million pixels in less than 8. 5 minutes at the current scanning rate.
Distances to points on a rough surface that reflects light in many directions can be determined to within 10 micrometers in half a millisecond with an accuracy that is traceable to a frequency standard.
The system has wide dynamic range enabling precise 3d mapping of targets with varied surface types and reflective properties.
LADAR typically measures distance based on the round-trip flight time of laser light which reflects off the target
In the NIST LADAR system the laser sweeps continuously across a band of frequencies. The initial laser output is combined with the reflected light
and the resulting beat signals are converted to voltage and analyzed by digital signal processing to generate time delay data
However by including a frequency comb to continuously calibrate the swept laser the NIST system can operate much more rapidly yielding one measurement point every half a millisecond
Comb-calibrated laser ranging for three-dimensional surface profiling with micrometer-level precision at a distance.
By shedding light on how the virus hijacks the transport system in nerve cells to reach its target organ with maximal speed and efficiency,
In detecting droplet size they found that a 30-cent component yielded results comparable to those from the traditional tool a $30000-plus optical microscope.
Spectroscopy showed that these artificial membranes were stable over a wide range of temperatures. More work is needed to standardize the process by
Different sensors see different wavelengths of light. Infrared is important for heat-seeking capabilities. UV imaging can be used to detect threats not seen in the visible spectrum.
A single window that could be produced using the NRL-developed nanocrystalline spinel would be transparent across many technologically important wavelengths easing design
#Laser scientists create portable sensor for nitrous oxide, methane Rice university scientists have created a highly sensitive portable sensor to test the air for the most damaging greenhouse gases.
and laser pioneer Frank Tittel and his group uses a thumbnail-sized quantum cascade laser (QCL) as well as tuning forks that cost no more than a dime to detect very small amounts of nitrous oxide and methane.
That allows for far better detection of gases than more common lasers that operate in the near-infrared.
The technique called quartz-enhanced photoacoustic absorption spectroscopy (QEPAS invented at Rice by Tittel, Professor Robert Curl and their collaborators in 2002,
and is far better able to detect trace amounts of gas than lasers used in the past.
"The laser beam is focused between the two prongs of the quartz tuning fork. When light at a specific wavelength is absorbed by the gas of interest,
localized heating of the molecules leads to a temperature and pressure increase in the gas."
"If the incident light intensity is modulated, then the temperature and pressure will be said as well, "Ren.""This generates an acoustic wave with the same frequency as the light modulation,
Co-authors include Rice graduate student Wenzhe Jiang and former Rice Laser Science Group members Przemystaw Stefanski, Rafat Lewicki, Jiawei Zhang and Jan Tarka.
The optical lattice was generated using two laser beams traveling in opposite directions, whose fields add up to form a sinusoidal periodic pattern in one dimension.
the group used light to ionize, or charge, neutral ytterbium atoms emerging from a small heated oven,
and then cooled them down with more laser light to just above absolute zero. The charged atoms can then be trapped using voltages applied to nearby metallic surfaces.
piston-driven engine that generates electricity causing a light to flash, and a rotary engine that drives a miniature car.
Coupling that piston to a generator produced enough electricity to cause a small light to flash. e turned evaporation from a pool of water into light,
With its current power output, the floating evaporation engine could supply small floating lights or sensors at the ocean floor that monitor the environment,
using ultraviolet light. The end result is safe drinking water that also tastes good. Earlier this year, Wright team won a grant from the United states Agency for International Development (USAID),
and detecting the difference between how the molecules absorb the light. But the distinguishing effects are weak tiny fractions of a per cent so the technique struggles to approach the sensitivity of the human nose.
Mass-Selected Photoelectron Circular Dichroism (MS-PECD) uses circularly polarised light produced by a laser to ionise the molecules using a couple of photons to knock an electron out of the chiral molecule to leave a positively charged ion behind.
either forwards or backwards along the laser beam it is possible to distinguish between left and right handed molecules with an accuracy of up to several tens of per cent rather than a fraction of a per cent.
They absorb ultraviolet and optical light, re-emitting the energy as infrared light, and thus they both constrain
what astronomers can see and control much of the energy balance in the interstellar medium. Not least, in the early stages of a star evolution the dust can coagulate into large clumps the first step towards forming planets.
The photonics experiments were performed at UC San diego Qualcomm Institute by researchers from the Photonics Systems Group led by Radic.
Other members of the research team were Evgeny Myslivets, Lan Liu and Vahid Ataie, all of the UC San diego Photonics Systems Group.
#MIT Chemists Develop a Quantum dot Spectrometer Researchers from MIT have designed a quantum dot spectrometer that is small enough to function within a smartphone, enabling portable light analysis. Instruments that measure the properties of light,
Shrinking spectrometers The earliest spectrometers consisted of prisms that separate light into its constituent wavelengths
while current models use optical equipment such as diffraction gratings to achieve the same effect. Spectrometers are used in a wide variety of applications,
which determines the wavelengths of light that each dot will absorb. However, most of the existing applications for quantum dots don take advantage of this huge range of light absorbance.
which rely on the dotsability to convert light into electrons. However, this phenomenon is understood not well,
Broad spectrum The new quantum dot spectrometer deploys hundreds of quantum dot materials that each filter a specific set of wavelengths of light.
and placed on top of a photodetector such as the charge-coupled devices (CCDS) found in cellphone cameras. The researchers created an algorithm that analyzes the percentage of photons absorbed by each filter,
then recombines the information from each one to calculate the intensity and wavelength of the original rays of light.
the more wavelengths can be covered and the higher resolution can be obtained. In this case, the researchers used about 200 types of quantum dots spread over a range of about 300 nanometers.
or to measure exposure to different frequencies of ultraviolet light, which vary greatly in their ability to damage skin. he central component of such spectrometers the quantum dot filter array is fabricated with solution-based processing and printing,
whereas LHCB conducted the search with the lights on, and from all angles. The next step in the analysis will be to study how the quarks are bound together within the pentaquarks. he quarks could be tightly bound
#Nanoparticles and UV LIGHT Clean up Environmental Pollutants A new study from MIT shows how nanoparticles can clean up environmental pollutants,
and UV LIGHT can rapchemicals for easy removal from soil and water. Many human-made pollutants in the environment resist degradation through natural processes,
and ultraviolet (UV LIGHT to quickly isolate and extract a variety of contaminants from soil and water.
Brandl had synthesized previously polymers that could be cleaved apart by exposure to UV LIGHT. But he and Bertrand came to question their suitability for drug delivery,
since UV LIGHT can be damaging to tissue and cells, and doesn penetrate through the skin.
When they learned that UV LIGHT was used to disinfect water in certain treatment plants, they began to ask a different question. e thought
if they are already using UV LIGHT, maybe they could use our particles as well, Brandl says. hen we came up with the idea to use our particles to remove toxic chemicals, pollutants,
because we saw that the particles aggregate once you irradiate them with UV LIGHT. trap for ater-fearingpollutionthe researchers synthesized polymers from polyethylene glycol,
But when exposed to UV LIGHT, the stabilizing outer shell of the particles is shed, and now nrichedby the pollutants they form larger aggregates that can then be removed through filtration, sedimentation,
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