Synopsis: Domenii: Photonics & laser: Photonics & laser colaterale:


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"The unique three-dimensionality interconnected nanoporous nature of our coatings significantly suppresses Fresnel light reflections from glass surfaces, providing enhanced transmission over a wide range of wavelengths and angles,

The Fresnel effect describes the amount of light that is reflected versus the amount transmitted. Where solar panels are concerned,

the suppression of reflected light translates into a 3-6 percent relative increase in light-to-electricity conversion efficiency and power output of the cells.

the coating is highly effective at blocking ultraviolet light. Other potential applications include goggles, periscopes, optical instruments, photodetectors and sensors.

Broadband/Omnidirectional Light Harvesting and Self-Cleaning Characteristics,"were Andrew Lupini, Gerald Jellison, Pooran Joshi, Ilia Ivanov, Tao Liu, Peng Wang, Rajesh


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That means little light is lost and the quantum efficiency is virtually very high. In addition, it has been reported in the very recently published article that the composite shows high long-term stability over 25 hours


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When exposed to green light, these centres emit a red fluorescent light, useful for sub-cellular imaging applications.

Unlike ordinary fluorescent material, these centres can also be turned into hypersensitive nanoprobes to detect temperature and magnetic field, via optical manipulation and detection.


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"Hybrid approaches such as ours bring together multiple capabilities, in this case, spectroscopy and high-resolution microscopy.""Looking inside, the hybrid microscope consists of a photonic module that is incorporated into a mode-synthesizing atomic force microscope.


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near-field optical microscopy and ultra-fast spectroscopy. Computer-assisted technology developed especially for this purpose combines the advantages of both methods

microscopy and ultra-fast spectroscopy. It enables unaltered optical measurements of extremely small, dynamic changes in biological, chemical or physical processes.

This creates highly bundled light-a hundred times smaller than the wavelength of light, which otherwise represents the limit of"normal"optics with lenses and mirrors."

"In principle, we can use the entire wavelength spectrum of near-field microscopy, from ultraviolet to the terahertz range,"says Dr. Susanne Kehr from the TU Dresden."

"The focused light delivers energy to the sample, creating a special interaction between the point and the sample in

Using ultra-fast spectroscopy is the crucial tool, on the other hand, enabling scientists to study dynamic processes on short timescales and with extreme sensitivity.

The principle in such pump-probe experiments that function, for example, with light, pressure or electric field pulses is as follows:

which--in addition to the outstanding resolution of near-field optical microscopy that is at least three orders of magnitude better than the resolution of common ultra-fast spectroscopy--we can now also measure dynamic changes in the sample with high sensitivity,

Universal in every respect"With our nanoscope's considerable wavelength coverage, dynamic processes can be studied with the best suited wavelengths for the specific process under study.

Our colleagues at the Freie Universität Berlin have, for example, the ambitious dream of tracking structural changes during the photocycle of an individual membrane protein at specific wavelengthes in the infrared spectrum,

The probe pulse wavelengths can, in principle, reach from the low terahertz range to the ultraviolet range.


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and then fixed them in place using a procedure called light-triggered in-situ vinyl polymerization, which essentially uses light to congeal a substance into a hydrogel.

The nanosheets ended up stuck within the polymer, aligned in a single plane. Due to electrostatic forces, the sheets create electrostatic resistance in one direction but not in the other.


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when they are exposed to near-infrared light. In addition, a gene therapy is administered that lowers the cellular defense against reactive oxygen species. Both the phthalocyanine

this approach allows the near-infrared light to penetrate much deeper into abdominal tissues, and dramatically increases the effectiveness of the procedure in killing cancer cells.

"and fluoresce when exposed to near-infrared light. This provides a literal road map for surgeons to follow,


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#New optical chip lights up the race for quantum computer The microprocessor inside a computer is a single multipurpose chip that has revolutionised people's life,

Now, researchers from the University of Bristol in the UK and Nippon Telegraph and Telephone (NTT) in Japan, have pulled off the same feat for light in the quantum world by developing an optical chip that can process photons in an infinite number

and control quantum states of light and matter. A major barrier in testing new theories for quantum science and quantum computing is the time


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Berkeley Lab scientist invents technique to combine spectroscopy with super-resolution microscopy, enabling new ways to examine cell structures

Berkeley Lab scientist invents technique to combine spectroscopy with super-resolution microscopy, enabling new ways to examine cell structures

The research was reported in the journal Nature Methods in a paper titled,"Ultrahigh-throughput single-molecule spectroscopy and spectrally resolved super-resolution microscopy"


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while still allowing light and electrons to pass through. The new complete solar fuel generation system developed by Lewis


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and convert the light into electric current using excited states in the material called"excitons.""Roughly speaking, an exciton is displaced a electron bound together with the hole it left behind.

The instrument combines a specialized form of linearly polarized light and photoluminescence to optically probe the molecular structure of the phthalocyanine crystals."


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At the Frontiers in Optics conference researchers will describe a custom-built ultrafast laser that could help image everything from semiconductor chips to cells in real time Using ultrafast beams of extreme ultraviolet light streaming at a 100,000 times a second, researchers

Not only did they make the highest resolution images ever achieved with this method at a given wavelength,

The researchers'wanted to improve on a lensless imaging technique called coherent diffraction imaging, which has been around since the 1980s.

creating a diffraction pattern. By analyzing that pattern, a computer then reconstructs the path those photons must have taken,

With more photons, at a wavelength of 33 nanometers, the researchers were able to make an image with a resolution of 26 nanometers--almost the theoretical limit."

"Nobody has achieved such a high resolution with respect to the wavelength in the extreme ultraviolet before, "Zürch said.

The ultrafast laser also overcame another drawback of conventional table-top light sources: long exposure times.

Thanks to the new high-speed light source, Zürch and his colleagues have reduced the exposure time to only about a second--fast enough for real-time imaging.


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The new material, produced by grain boundary lithography, solves that problem, he said. In addition to Ren, other researchers on the project included Chuan Fei Guo and Ching-Wu"Paul"Chu, both from UH;

The grain boundary lithography involved a bilayer lift off metallization process, which included an indium oxide mask layer and a silicon oxide sacrificial layer and offers good control over the dimensions of the mesh structure.


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the less efficient they become at converting the photons in light into useful electricity. The Stanford solution is based on a thin,

in the form of infrared light, into space. Their experiments showed that the overlay allowed visible light to pass through to the solar cells,

but that it also cooled the underlying absorber by as much as 55 degrees Fahrenheit. For a typical crystalline silicon solar cell with an efficiency of 20 percent, 55 F of cooling would improve absolute cell efficiency by over 1 percent,

perhaps using nanoprint lithography, which is a common technique for producing nanometer scale patterns.""That's not necessarily the only way,"said Raman, a co-first-author of the paper."

"That's because the perception of color requires objects to reflect visible light, so any overlay would need to be tuned transparent,

"Our photonic crystal thermal overlay optimizes use of the thermal portions of the electromagnetic spectrum without affecting visible light,


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#Pioneering research develops new way to capture light--for the computers of tomorrow Pioneering research by an international team of scientists,

data transfer by means of light-have long since become part of our everyday life, data on a computer are processed still

The team of scientists from Germany and England have made a key breakthrough by capturing light on an integrated chip,


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this tool should provide fast and reliable characterization of the different mechanisms cellular proteins use to bind to DNA strands--information that could shed new light on the atomic-scale interactions within our cells


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The work demonstrates the potential of low energy electron holography as a non-destructive, single-particle imaging technique for structural biology.

"We've shown that by means of low energy holography, it is possible to image individual tobacco mosaic virions deposited on ultraclean freestanding graphene,

Low energy electron holography is a technique of using an electron wave to form holograms. Similar to light optical holography

albeit with a much smaller wavelength, the complete information of the scattered wave, such as phase and amplitude, is recorded

thus enabling an unambiguous reconstruction of the object's structure.""The low energy electron holography has two major advantages over conventional microscopy.

First, the technique doesn't employ any lenses, so the resolution won't be limited by lens aberration.

in low energy electron holography, the employed electron doses can be much higher--even after exposing fragile molecules like DNA or proteins to a electron dose more than five orders of magnitude higher

Sufficient electron dose in low energy electron holography makes imaging individual biomolecules at a nanometer resolution possible.

To obtain the high-resolution hologram, an atomically sharp, tungsten tip acts as a source of a divergent beam of highly coherent electrons.

the researchers recorded the sample's high-resolution hologram, a pattern resulting from the interference of the two beams."

"Since low energy electron holography is a method very sensitive to mechanical disturbance, the current nanometer resolution could be improved to angstrom (one ten billionth of a meter)


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"In this light, Lu's invention represents a major advancement for the mobile health industry.""After producing the cut-and-pasted patches,


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we have made two major advances--the ability to precisely control the brightness of light-emitting particles called quantum dots,

because the amount of light emitted from a single dye is unstable and often unpredictable.

These attributes obscure correlations between measured light intensity and concentrations of molecules,"stated Sung Jun Lim, a postdoctoral fellow and first author of the paper"

and improve color tuning in light-emitting devices. In addition, BE-QDS maintain their equal brightness over time


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Chance effect of lab's fluorescent lights leads to discovery In contrast to using advanced nanofabrication facilities based on chemical processing of materials,

"It's one of those rare moments in experimental science where a seemingly random event--turning on the room lights--generated unexpected effects with potentially important impacts in science and technology."

"There was a slow drift in our measurements that we traced to a particular type of fluorescent lights in our lab. At first we were glad to be rid of it,

and then it struck us--our room lights were doing something that people work very hard to do in these materials."

the contractor that renovated the lab space for more information about the lights.""I've never had a client

when exposed to ultraviolet light, and their room lights happened to emit at just the right wavelength.

The electric field from the polarized strontium titanate was leaking into the topological insulator layer, changing its electronic properties.

Awschalom and his colleagues found that by intentionally focusing beams of light on their samples,

they could draw electronic structures that persisted long after the light was removed.""It's like having a sort of quantum etch-a-sketch in our lab,

They also found that bright red light counteracted the effect of the ultraviolet light, allowing them to both write and erase."


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In this case, the light has a much lower frequency than ordinary light and in reality is microwaves."


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#Researchers transform slow emitters into fast light sources Researchers from Brown University, 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,

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.


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Among other advantages of the cells, mention can be made of simple production method, appropriate final price and high transparency for the light.


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when you look at an object illuminated by a single frequency of light, 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.

"We 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, "says Hsieh."


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but uses photons--the quanta of light--instead of electrons. The biggest advantage of using photons is the absence of interactions between them.

Nanoparticles were fabricated in the Australian National University by e-beam lithography followed by plasma-phase etching.


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Due to this short wavelength, it is possible to visualize even single atoms in diffraction experiments. If such electrons meet a molecule or atom,

they are diffracted into specific directions due to their short wavelength. This way they generate an interference pattern at the detector from

the physicists applied their ultrashort electron pulses to a biomolecule in a diffraction experiment. It is planned to use those electron beams for pump-probe experiments:

Shortly afterwards the electron pulses produce a diffraction image of the structure at a sharp instant in time.

Thanks to the subatomic wavelength of the electrons, one therefore obtains a spatial image as well as the dynamics.

The aim of the scientists is to eventually observe even the much faster motions of electrons in light-driven processes o


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The Optical Society) By precisely etching tiny features--smaller than a wavelength of light--onto a silicon film one thousand times thinner than a human hair, the researchers were able to select the range of colors the material would reflect,

or wavelengths of light. Those that aren't absorbed are reflected back with shorter wavelengths giving objects a blue hue and longer wavelengths appearing redder and the entire rainbow of possible combinations in between.

Changing the color of a surface, such as the leaves on the trees in autumn, requires a change in chemical make-up.

and reflect particular wavelengths of light. This type of"structural color"is much less common in nature

Controlling light with structures rather than traditional optics is not new. In astronomy, for example, evenly spaced slits known as diffraction gratings are used routinely to direct light

and spread it into its component colors. Efforts to control color with this technique, however, have proved impractical

Rather than spreading the light into a complete rainbow, however, these ridges--or bars--reflect a very specific wavelength of light.

By"tuning"the spaces between the bars, it's possible to select the specific color to be reflected.

Unlike the slits in a diffraction grating, however, the silicon bars were extremely efficient and readily reflected the frequency of light they were tuned to.

Flexibility Is the Key to Control Since the spacing, or period, of the bars is the key to controlling the color they reflect,

spaced so they can interact with a specific wavelength of light, you can change its properties

and how it interacts with light by changing its dimensions, "said Chang-Hasnain. Earlier efforts to develop a flexible,

reflecting only a portion of the light they received. Other surfaces were too thick, limiting their applications,

orange, and red-across a 39-nanometer range of wavelengths. Future designs, the researchers believe,

and reflect light with even greater efficiency. Chameleon Skin with Multiple Applications For this demonstration, the researchers created a one-centimeter square layer of color-shifting silicon.


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The optical coupling is also wavelength and polarization insensitive and tolerant to alignment offsets of a few micrometers,


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#Nanospheres cooled with light to explore the limits of quantum physics A team of scientists at UCL led by Peter Barker

"Nanospheres were cooled with light to explore the limits of quantum physics. Image: James Millen et al. Quantum phenomena are strange and unfamiliar.

which has a very carefully calibrated wavelength. The laser light can hold the particle steady (a phenomenon known as optical tweezing)


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called CLIP-for Continuous Liquid Interface Production-manipulates light and oxygen to fuse objects in liquid media,

It works by projecting beams of light through an oxygen-permeable window into a liquid resin.

Working in tandem, light and oxygen control the solidification of the resin, creating commercially viable objects that can have feature sizes below 20 microns,

"CLIP's debut coincides with the United Nation designating 2015 as the International Year of Light and Light-Based Technologies,


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which comprises a small modulation in the optical material properties, forms a bandgap for light,

which strongly effects the propagation of light, in the same way that semiconductors control the flow of electrons.


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but under low light and at night, they're still vulnerable to infrared detection, "explains Alon Gorodetsky,

The current version reflects near-infrared light. Gorodetsky's team is continuing to tweak the materials,

so variants of the stickers could also work at mid-and far-infrared wavelengths. These could have applications for thwarting thermal infrared imaging.


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spectral selective perfect light absorption in single layer silicon films on aluminum surface and its thermal tunability".

and chemical materials are caused by wavelength selective light absorption in organic molecules. Currently, colors on computer and iphone screens come from dye materials pre-placed on the pixels.

is because one wavelength of light is absorbed completely, explains Dr. Guo, while his student holds a collection of color samples.

A lot of colors you see in nature are due to wavelength selective light absorption in organic molecules which cannot withstand high temperatures,

Ultraviolet light destroys organic dye molecules over time, leading to color change and fading. The new technology may hold promise for many applications such as for jewelry, automotive interior trim, aviation, signage, colored keypads, electronics and wearable displays s


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making them light, flexible and highly adaptable. They operate silently and are relatively cheap to produce.


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however, has very little interaction with light, limiting the material's use in light emitting and absorbing applications."

"The problem with these materials is that they are just one monolayer thick, "said Koray Aydin, assistant professor of electrical engineering and computer science at Northwestern University's Mccormick School of engineering."

"So the amount of material that is available for light emission or light absorption is limited very. In order to use these materials for practical photonic and optoelectric applications,

the research is described in the March 2015 online issue of Nano Letters("Enhanced Light Emission from Large-Area Monolayer Mos2 Using Plasmonic Nanodisc Arrays").

With enhanced light emission properties, Mos2 could be a good candidate for light emitting diode technologies.

The team's next step is to use the same strategy for increasing the material's light absorption abilities to create a better material for solar cells and photodetectors."


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Using photoacoustic microscopy (PAM), a single wavelength, pulse-width-based technique developed in his lab, Wang,

"Using this new single wavelength, pulse-width-based method, PAM is speed capable of high imaging of the oxygen saturation of hemoglobin,


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and PSB formed the shell to create an nversemicelle. he material is controlled easily by salt alone, rather than by a combination of several stimuli like ph, temperature or light,


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and Light Extremely stiff carbon fiber components reduce the inertia and result in a high Eigenfrequency of 200hz, important for fast response, high operating frequencies,


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The intensity of the emitted light carries information about the vacancy magnetic state. n the past

The MIT researchers report their new device in the latest issue of Nature Physics("roadband Magnetometry and Temperature Sensing with a Light Trapping Diamond Waveguide".


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engineers will need a 3-dimensional image depicting how light interacts with these objects on the nanoscale.

Unfortunately, the physics of light has thrown up a roadblock in traditional imaging techniques: the smaller the object, the lower the image's resolution in 3-D. Now, engineers at Stanford and the FOM Institute AMOLF, a research laboratory in The netherlands, have developed a technique that makes it possible to visualize the optical properties of objects that are several

The research is detailed in the current issue of Nature Nanotechnology("Nanoscale optical tomography with cathodoluminescence spectroscopy".

Both the intensity and the wavelength of the emitted photons depended on which part of the object the electron beam excited,

For instance, the gold shell at the base of the object emitted photons of shorter wavelengths than

Each pixel in this image also contained information about the wavelength of emitted photons across visible and near-infrared wavelengths.

which light interacts with this nanometer scale object.""Interpreting a 2-D image, however, can be quite limiting,

techniques to image light-matter interactions with sub-diffraction-limited resolution have been limited to 2d.""This work could enable a new era of 3d optical imaging with nanometer scale spatial and spectral resolution,

The technique can be used to probe many systems in which light is emitted upon electron excitation."

"For instance, it could be used in manufacturing LEDS to optimize the way light is emitted, or in solar panels to improve the absorption of light by the active materials."

"The technique could even be modified for imaging biological systems without the need for fluorescent labels.


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Photolithography is a standard optical process for transferring micropatterns on to a substrate by exposing specific regions of the photoresist layer to ultraviolet (UV LIGHT.

Conventional photolithography relied on photomasks which protected certain regions of the substrate from the input UV LIGHT.

Areas covered by the photomasks remain intact with the base layer while the areas exposed to the UV LIGHT are washed away,

thus creating a micropattern. This technology was limited to a two-dimensional, disc-shaped design as the boundaries between the exposed and roofed regions are always in a parallel arrangement with the direction of the light.

Professor Kim research team discovered that: 1) the areas exposed to UV LIGHT lowered the concentration of oxygen

and thus resulted in oxygen diffusion; and 2) manipulation of the diffusion speed and direction allowed control of the growth,

Photoresist under UV LIGHT creates radicals which initialize a chemical reaction. These radicals are eliminated with the presence of oxygen

This suggests that the photoresist must be exposed to UV LIGHT for an extended time to completely remove oxygen for a chemical reaction to begin.

While the region affected by the UV LIGHT lowered oxygen concentration, the concentration in the untouched region remained unchanged.

This difference in the concentrations caused a diffusion of oxygen to the region under UV LIGHT.

the diffusion occurs in parallel with the direction of the UV LIGHT. When fast, the diffusion process develops horizontally,

outward from the area affected by the UV LIGHT. Professor Kim and his team proved this phenomenon both empirically and theoretically.


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The paper("Probing the Molecular Architecture of Arabidopsis thaliana Secondary cell Walls Using Two-and Three-dimensional 13c Solid State Nuclear Magnetic resonance Spectroscopy")describing this work was Editors Choice for the American

NMR spectroscopy is a vital analytical tool across science. It is a powerful technique that can provide detailed information on the three-dimensional structure and dynamics of molecules in solution and the solid state e


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Today the most commercially successful organic electronic devices are OLEDS (organic light emitting diodes) found in smart phone displays.

) The team was able to design an organic electronic device in which charge generated by light lived approximately 10,000 times longer than was thought previously possible.


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#Graphene pushes the speed limit of light-to-electricity conversion (Nanowerk News) The efficient conversion of light into electricity plays a crucial role in many technologies,

since it allows for information carried by light to be converted into electrical information that can be processed in electrical circuits.

Graphene is an excellent material for ultrafast conversion of light to electrical signals, but so far it was known not how fast graphene responds to ultrashort flashes of light.

"The new device that the researchers developed is capable of converting light into electricity in less than 50 femtoseconds (a twentieth of a millionth of a millionth of a second.

Thus, the energy absorbed from light is efficiently and rapidly converted into electron heat. Next, the electron heat is converted into a voltage at the interface of two graphene regions with different doping.

thus enabling the ultrafast conversion of absorbed light into electrical signals. As Prof. van Hulst states"


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STEVE The value measured by the 3d Cell Explorer is not fluorescence intensity of an exogenous molecule like with most optical microscopes.

In contrast, Nanolives technology detects the physical refractive index of the different cell parts with resolution far beyond the diffraction limit (see Nobel prize 2014 for chemistry.

which overcomes the inherent limitations of light, and pushes it far beyond the physical limits previously thought possible.


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