and using a blue backlight to energize them, QD Vision has developed an optical component that can boost the color gamut for LCD televisions by roughly 50 percent,
pixels are illuminated by a white LED backlight that passes through blue, red, and green filters to produce the colors on the screen.
But this actually requires phosphors to convert a blue light to white; because of this process, much light is lost,
and displays only reach about 70 to 80 percent of the National Television Standard Committee color gamut.
Manufacturers use a blue LED in the backlight, but without the need for conversion phosphors.
As blue light passes through the Color IQ tube, some light shines through as pure blue light
With more light shining through the pixels, LCD TVS equipped with Color IQ produce 100 percent of the color gamut,
However this DNA is produced only when activated by the presence of a predetermined molecule or another type of input such as light.
which can be identified with great precision by the wavelength of their fluorescent emissions. The new method produces the combination of desired properties in as small a package as possible Bawendi says which could help pave the way for particles with other useful properties such as the ability to bind with a specific type of bioreceptor or another
The emitters like most nanoscale silicon devices were produced through photolithography a process in which patterns are transferred optically to layers of materials deposited on silicon wafers;
Nanoprintingvelsquez-Garca believes that using arrays of emitters to produce nanodevices could have several advantages over photolithography the technique that produces the arrays themselves.
It should absorb virtually all wavelengths of light that reach Earth s surface from the sun but not much of the rest of the spectrum since that would increase the energy that is reradiated by the material
Most of the sun s energy reaches us within a specific band of wavelengths Chou explains ranging from the ultraviolet through visible light and into the near-infrared.
or when its distance is a specific multiple of the wavelength of sound. Maintaining that precise distance is a tall order
Companies sell medications with barcodes others sell software or barcode scanners. Hospitals have to make all these things work together
Furthermore the researchers found that they could reverse the emotional association of specific memories by manipulating brain cells with optogenetics a technique that uses light to control neuron activity.
Then for mice that had received the fear conditioning the researchers stimulated the labeled cells in the dentate gyrus with light
For male mice that had received originally the fear conditioning they activated the memory cells involved in the fear memory with light for 12 minutes while the mice spent time with female mice.
but also light much as window blinds tilt to filter the sun. Researchers say the work could lead to waterproofing and anti-glare applications such as smart windows for buildings and cars.
and found she could control how much light passed through based on the angle at which the pillars bent.
But at the boundary itself, the camera sensor receives both red and blue light, so it averages them out to produce purple.
#Light pulses control graphene s electrical behavior Graphene, an ultrathin form of carbon with exceptional electrical optical and mechanical properties, has become a focus of research on a variety of potential uses.
Now researchers at MIT have found a way to control how the material conducts electricity by using extremely short light pulses
which could enable its use as a broadband light detector. The new findings are published in the journal Physical Review Letters in a paper by graduate student Alex Frenzel Nuh Gedik and three others.
The researchers found that by controlling the concentration of electrons in a graphene sheet they could change the way the material responds to a short but intense light pulse.
The researchers then illuminated graphene with a strong light pulse and measured the change of electrical conduction by assessing the transmission of a second low-frequency light pulse.
We use two different light pulses: one to modify the material and one to measure the electrical conduction.
Additionally the short light pulses allow the researchers to change and reveal graphene's electrical response in only a trillionth of a second.
The researchers say the work could aid the development of new light detectors with ultrafast response times and high sensitivity across a wide range of light frequencies from the infrared to ultraviolet.
While the material is sensitive to a broad range of frequencies the actual percentage of light absorbed is small.
The angle at which light should seem to arrive from the simulated image is sharper than the angle at
which light would arrive from the same image displayed on the screen. So the physical pixels projecting light to the right side of the pupil have to be offset to the left
That requires that a transparency patterned with an array of pinholes be laid over the screen blocking more than half the light it emits.
while letting much more light pass through. Wetzstein envisions that commercial versions of a vision-correcting screen would use the same technique.
In image-processing schemes with incoherent light normal light that we have around us nonlaser light you're always dealing with intensities.
#Making the cut Diode lasers used in laser pointers barcode scanners DVD players and other low-power applications are perhaps the most efficient compact and low-cost lasers available.
At the core of the Terablade is a power-scaling technique known as wavelength beam combining (WBC
when electrically charged cause electrons to create photons of the same wavelength or color traveling in the same direction.
and near-infrared wavelengths that can be focused tightly to a very small spot but with little power Huang explains.
Overlapping many similar beams at differing wavelengths however produces a beam that focuses on a small spot making it very intense.
And the number of overlapping beams with differing wavelengths can be very high. In the early 2000s Huang Chann and Lincoln Laboratory colleagues built a few prototype lasers based on WBC technology.
Today the WBC-based Terablade is a laser module that contains diode laser bars (long arrays of diode lasers) a transform lens a diffraction grating and an output lens.
The light from the diode lasers passes through a transform lens onto the carefully positioned diffraction grating a plate of glass scratched with parallel lines.
However instead of dispersing light at different angles which it s designed to do the grating forces the beams into the same direction superimposing them on one another.
or spatial beam combining that joins together the beams of similar wavelengths. As the number of diode lasers increases the beam quality degrades resulting in a large focused spot limiting the beam s intensity.
The brighter the light, the more steam is generated. The new material is able to convert 85 percent of incoming solar energy into steam a significant improvement over recent approaches to solar-powered steam generation.
and exposing it to a solar simulator a light source that simulates various intensities of solar radiation.
The team used various techniques including differential scanning calorimetry dynamic light scattering and microscopy to test the separation efficiency showing more than 99.9 percent separation.
#Noninvasive brain control Optogenetics, a technology that allows scientists to control brain activity by shining light on neurons,
This technique requires a light source to be implanted in the brain, where it can reach the cells to be controlled.
using a light source outside the skull. This makes it possible to do long-term studies without an implanted light source.
The protein, known as Jaws also allows a larger volume of tissue to be influenced at once. This noninvasive approach could pave the way to using optogenetics in human patients to treat epilepsy and other neurological disorders,
Researchers then insert a light source, such as an optical fiber, into the brain to control the selected neurons.
Most of the natural opsins now used for optogenetics respond best to blue or green light.
Boyden team had identified previously two light-sensitive chloride ion pumps that respond to red light, which can penetrate deeper into living tissue.
these molecules, found in the bacteria Haloarcula marismortui and Haloarcula vallismortis, did not induce a strong enough photocurrent an electric current in response to light to be useful in controlling neuron activity.
The result of this screen, Jaws, retained its red-light sensitivity but had a much stronger photocurrent enough to shut down neural activity. his exemplifies how the genomic diversity of the natural world can yield powerful reagents that can be of use in biology and neuroscience,
the researchers were able to shut down neuronal activity in the mouse brain with a light source outside the animal head.
and was just as effective as that of existing silencers that rely on other colors of light delivered via conventional invasive illumination.
and identifying the reasons for its broadband light absorption, have been daunting tasks. This is, in part, because of the very characteristics that make it so interesting:
Typically, the constituents of a chemical compound can be determined through spectroscopy, among other tools, but in the case of eumelanin the spectrographs don show the sharp peaks that are ordinarily useful in identification.
With this kind of microscope, the light emitted by the sample being imaged is sent through an array of lenses that refracts the light in different directions.
Each point of the sample generates about 400 different points of light, which can then be recombined using a computer algorithm to recreate the 3-D structure. f you have one light-emitting molecule in your sample,
rather than just refocusing it into a single point on the camera the way regular microscopes do,
these tiny lenses will project its light onto many points. From that you can infer the three-dimensional position of where the molecule was,
which enables neuronal firing to be controlled by shining light on cells engineered to express light-sensitive proteins.
which are like tiny liquid-crystal displays (LCDS) positioned between the light source and the lens. Patterns of light and dark on the first modulator effectively turn it into a bank of slightly angled light emitters that is,
light passing through it reaches the second modulator only at particular angles. The combinations of the patterns displayed by the two modulators
With the technology that has historically been used to produce glasses-free 3-D images known as a parallax barrier simultaneously projecting eight different viewing angles would mean allotting each angle one-eighth of the light emitted by the projector
Bridge technology Passing light through two modulators can also heighten the contrast of ordinary 2-D video.
One of the problems with LCD screens is that they don enable rue black A little light always leaks through even the darkest regions of the display. ormally you have contrast of,
so that it (a) doesn block as much light and (b) gets better resolution. The second, he says,
and the solid angle of light coming out from that plane, that is fixed, Cossairt says. hat that means is that
In 2013, they reported making the first solar cell that gives off extra electrons from high-energy visible light,
which makes up almost half the sun electromagnetic radiation at the Earth surface. According to their estimates, applying their technology as an inexpensive coating on silicon solar cells could increase efficiency by as much as 25 percent.
since the distance between sensors is proportional to wavelength. In the latest issue of IEEE Transactions on Antennas and Propagation researchers in MIT s Research Laboratory for Electronics describe a new technique that could reduce the number of sensors required for terahertz
In a digital camera the lens focuses the incoming light so that light reflected by a small patch of the visual scene strikes a correspondingly small patch of the sensor array.
In lower-frequency imaging systems by contrast an incoming wave whether electromagnetic or in the case of sonar acoustic strikes all of the sensors in the array.
As long as the distance between sensors is no more than half the wavelength of the incoming wave that calculation is fairly straightforward a matter of inverting the sensors measurements.
But if the sensors are spaced farther than half a wavelength apart the inversion will yield more than one possible solution.
including environmental pollutants, ultraviolet light, and radiation. Fortunately, cells have several major DNA repair systems that can fix this damage,
which DNA damage caused by ultraviolet light goes unrepaired and leads to skin cancer. Scientists have identified also links between DNA repair and neurological, developmental,
But these photoswitches can be triggered to return to the other configuration by applying a small jolt of heat, light,
when lit up with near-infrared light. These particles can easily be manufactured and integrated into a variety of materials,
when exposed to near-infrared light. By altering the ratios of these elements, the researchers can tune the crystals to emit any color in the visible spectrum.
To manufacture the particles, the researchers used stop-flow lithography, a technique developed previously by Doyle.
Wherever pulses of ultraviolet light strike the streams a reaction is set off that forms a solid polymeric particle.
anyone could image the particles after shining near-infrared light on them with a laser pointer. The researchers are also working on a smartphone app that would further process the images
#A new angle on controlling light Light waves can be defined by three fundamental characteristics: their color (or wavelength), polarization, and direction.
While it has long been possible to selectively filter light according to its color or polarization,
But now, for the first time, MIT researchers have produced a system that allows light of any color to pass through
While the amount of light reflected at each of these interfaces is small, by combining many layers with the same properties,
most of the light can be reflected away except for that coming in at precisely the right angle and polarization.
Previous work had demonstrated ways of selectively reflecting light except for one precise angle, but those approaches were limited to a narrow range of colors of light.
and light lost to reflections, and re-emission, so the ability to selectively control those reflections could improve efficiency.
roughly 90 percent of the light coming in within that angle was allowed to pass through. While these experiments were done using layers of glass and tantalum oxide,
calls this an ngenious application. n a macroscopic scale this is equivalent to observing the world through a set of louvers that allow light to enter from one direction only,
operating as it does on the length scale of a wavelength. The team also included MIT research scientist Ivan Celanovic;
Each type is specialized to respond to a particular variety of visual input for example, light or darkness, the edges of an object,
Other known ganglion types respond only when light is turned on or off, and still others monitor the overall level of light
the researchers used a light microscope to image individual neurons in the brains of mice that had been engineered genetically so that one class of ganglions,
which add functions such as conducting electricity or emitting light. The new materials represent a simple demonstration of the power of this approach
and run the sample through a machine that detects any light emitted. Results can be plugged into the company software,
because light and oxygen damage the photosynthetic proteins. Usually plants can completely repair this kind of damage,
and other highly reactive molecules produced by light and oxygen, protecting the chloroplasts from damage.
but carbon nanotubes could act as artificial antennae that allow chloroplasts to capture wavelengths of light not in their normal range, such as ultraviolet, green,
tumors failed to spread. his elegant study sheds new light into the extracellular matrix proteins involved in various steps of the metastatic cascade,
that sheds empirical light on the inner workings of health care in the U s. The study takes advantage of Oregon recent use of a lottery to assign access to Medicaid, the government-backed health-care plan for low-income
and it works much more reliably than lidar in bright sunlight when ambient light can yield misleading readings.
the new system just deploys that hardware in a manner more in tune with the physics of low light-level imaging and natural scenes.
In a conventional lidar system the laser fires pulses of light toward a sequence of discrete positions
which pulses of light are emitted and reflected photons are detected that it can rule out the misleading signals produced by stray photons.
The MIT researchers system by contrast fires repeated bursts of light from each position in the grid only until it detects a single reflected photon;
Fortunately the false readings produced by such ambient light can be characterized statistically; they follow a pattern known in signal processing as Poisson noise.
That could mean that you have a light source that s weak or it could be that you re interrogating a biological sample
and too much light could damage it. Our eyes are a very good example of this but other biological systems are the same.
which the location of objects is calculated by how long it takes a light signal to reflect off a surface and return to the sensor.
"Kadambi says. hat is because the light that bounces off the transparent object and the background smear into one pixel on the camera.
In a conventional Time of Flight camera, a light signal is fired at a scene where it bounces off an object
In 2011 Raskar group unveiled a trillion-frame-per-second camera capable of capturing a single pulse of light as it travelled through a scene.
Conventional cameras see an average of the light arriving at the sensor, much like the human eye, says James Davis, an associate professor of computer science at the University of California at Santa cruz. In contrast,
what happens when they take a camera fast enough to see that some light makes it from the lashback to the camera sooner,
the researchers shine ultraviolet light through a mask onto a stream of flowing building blocks, or oligomers.
#Persuading light to mix it up with matter Researchers at MIT have succeeded in producing and measuring a coupling of photons
Their method involves shooting femtosecond (millionths of a billionth of a second) pulses of mid-infrared light at a sample of material and observing the results with an electron spectrometer, a specialized high-speed camera the team developed.
it may be possible to do this just by shining light on it. That actually modifies how electrons move in this system.
the light does not even get absorbed. g
#Anklebot helps determine ankle stiffness For most healthy bipeds, the act of walking is given seldom a second thought:
or lights, or battery packs, or other equipment, which the mobile cubes could transport. n the vast majority of other modular systems,
which relies on near-infrared light, could help scientists learn more about diseased or infected cells as they flow through silicon microfluidic devices. his has the potential to merge research in cellular visualization with all the exciting things you can do on a silicon wafer,
and colleagues took advantage of the fact that silicon is infrared transparent to and near-infrared wavelengths of light.
which produces visible light, but for the new system the researchers used a titanium sapphire laser that can be tuned to infrared and near-infrared wavelengths.
For this study, the researchers found that light with a wavelength of 980 nanometers worked best.
Using this system, the researchers measured changes in the height of red blood cells, with nanoscale sensitivity,
if the wavelength of light is increased into the infrared range. The researchers are also working on modifying the system
optical waveguides to carry light, hollow tubes to carry drugs, and conductive electrodes to carry electrical signals.
For example, light could be transmitted through the optical channels to enable optogenetic neural stimulation, the effects
or silence neurons with pulses of light, a method called optogenetics. Activating the projections led to compulsive sucrose-eating
They say this has the potential to lead to new kinds of light detection, thermal-management systems,
Although the two materials are structurally similar both composed of hexagonal arrays of atoms that form two-dimensional sheets they each interact with light quite differently.
The hybrid material blocks light when a particular voltage is applied to the graphene, while allowing a special kind of emission and propagation,
One of the consequences of this unusual behavior is that an extremely thin sheet of material can interact strongly with light,
while light interacting with hbn produces phonons. Fang and his colleagues found that when the materials are combined in a certain way,
The properties of the graphene allow precise control over light, while hbn provides very strong confinement and guidance of the light.
Combining the two makes it possible to create new etamaterialsthat marry the advantages of both,
says, he combination of these two materials provides a unique system that allows the manipulation of optical processes. he combined materials create a tuned system that can be adjusted to allow light only of certain specific wavelengths
comes from the ability to switch a light beam on and off at the material surface; because the material naturally works at near-infrared wavelengths, this could enable new avenues for infrared spectroscopy,
he says. t could even enable single-molecule resolution, Fang says, of biomolecules placed on the hybrid material surface.
says, his work represents significant progress on understanding tunable interactions of light in graphene-hbn.
the group used light to ionize, or charge, neutral ytterbium atoms emerging from a small heated oven,
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,
if light is polarized so that it runs parallel to the long axis of organic solar cell molecules it will be absorbed;
This design allowed the researchers to make the organized areas of the cell effectively invisible by controlling the polarity of light aimed at the active layer.
Conventional pigments produce colors by selectively absorbing light of different wavelengths#for example red ink appears red
A similar effect can be realized at a much smaller scale by using arrays of metallic nanostructures since light of certain wavelengths excites collective oscillations of free electrons known as plasmon resonances in such structures.
This enhanced resolution at the diffraction limit of light is critical for data storage digital imaging and security applications.
The plasmon resonance wavelength varies sensitively with the dimensions of the nanostructures. Consequently by varying the diameter of the four aluminum nanodisks in a pixel (all four nanodisks having the same diameter) the scientists were able to produce about 15 distinct colors#a good start
when struck by near-infrared light, and an outer fabric of porphyrin-phospholipids (Pop) that wraps around the core.
when struck by near-infrared light, and an outer fabric of porphyrin-phospholipids (Pop) that wraps around the core.
Sequential printing of different types of QDS in a multilayer stack or in an interdigitated geometry provides strategies for continuous tuning of the effective overall emission wavelengths of the resulting QD LEDS.
and spectroscopy complemented with first principles theoretical calculations has shown that it gives rise to a system with very interesting electronic properties
#Researchers create novel nanobowl optical concentrator for organic solar cell Geometrical light trapping is a simple and promising strategy to largely improve the optical absorption and efficiency of solar cells.
Nonetheless implementation of geometrical light trapping in organic photovoltaic (OPV) is challenging due to the fact that uniform organic active layer can rarely be achieved on textured substrate.
Nanobowl optical concentrator for efficient light trapping and high-performance organic photovoltaics. Science Bulletin. DOI: 10.1007/s11434-014-0693
To do this they integrated an electromagnetic tweezers with an optical microscope and used a novel microfluidic chip to monitor the interaction of individual nanorods with two human breast cancer cell lines that express the Erbb family of receptors at different rates.
allowing the device to project beams of colored light. Michael Mcalpine the lead researcher cautioned that the lens is designed not for actual use for one it requires an external power supply.
The researchers used tiny crystals called quantum dots to create the LEDS that generated the colored light.
Traditional manufacturing which uses lithography to create electronic components is a fast and efficient way to make multiple copies with a very high reliability.
#New technique allows low-cost creation of 3-D nanostructures Researchers from North carolina State university have developed a new lithography technique that uses nanoscale spheres to create three-dimensional (3-D) structures
Most conventional lithography uses a variety of techniques to focus light on a photosensitive film to create 2-D patterns.
but bend and scatter the light that passes through them in predictable ways according to the angle that the light takes when it hits the nanosphere.
The researchers control the nanolithography by altering the size of the nanosphere the duration of light exposures and the angle wavelength and polarization of light.
The researchers can also use one beam of light or multiple beams of light allowing them to create a wide variety of nanostructure designs.
We are using the nanosphere to shape the pattern of light which gives us the ability to shape the resulting nanostructure in three dimensions without using the expensive equipment required by conventional techniques Chang says.
And it allows us to create 3-D structures all at once without having to make layer after layer of 2-D patterns.
which are used commonly in lithography Zhang says. But the technique could also be used to create templates for 3-D structures using other materials.
Designing complex structures beyond the capabilities of conventional lithography More information: The paper Sculpting Asymmetric Hollow-Core Three-dimensional Nanostructures Using Colloidal Particles was published online Dec 8 in the journal Small l
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