Post by williamplayer on Apr 23, 2014 11:22:53 GMT
Graphene ‘Spaser’ Brings Optical Computing to the Nano-scale
New research in an area called plasmonics has raised hopes for all sorts of seemingly implausible inventions, like cancer-killing nanotubes and mobile phones printed into t-shirts. It’s yet another breakthrough we can chalk up to carbon nanotubes and their sister material graphene, which have allowed researchers to replicate the functions of a laser on a much smaller scale than boring old light could ever allow.
One of the biggest problems with using light for industry is that it does not scale. Light of a particular color has a set wavelength, and that wavelength remains static regardless of the size of the generator; the green light of a pocket-sized laser pointer can have the same wavelength as that produced by a building-sized space-laser
This has the big advantage of providing astronomers with sensible optical information about the rest of the universe, but it also places a hard limit on miniaturization of optical devices. At scales smaller than about half the wavelength of the light being created, it’s impossible to do useful optical work. For reference, visible light runs from about 400 to about 700 nanometers in wavelength, meaning light in that range is dozens of times fatter than the scale of modern transistors.
One proposed solution to this problem is called Surface Plasmon Amplification by Stimulated Emission of Radiation, or a “spaser.” Spasers are generally referred to as nano-scale lasers, though the two technologies seem to have few similarities. Spasers basically trade photons for resonating electrons, sending optical signals called surface plasmons down the a physical substrate (thus, the field is called plasmonics). This differs from electrical conductivity in that when these surface plasmons reach their destination at the other end of the spaser, they behave like photons of light in every way that matters to a computer engineer.
Until now, the only appropriate substrate for a spaser has been bunches of quantum dots or nanoparticles of precious metal. Graphene, however, has the electrical and optical properties needed for a spaser, along with the added bonus of being strong enough for use in the real world. Graphene is an almost theoretically small substance, just a single atom thick in its purest form; this is one of the smallest sorts of computing possible.
Read Full Article: www.extremetech.com/extreme/180728-graphene-spaser-brings-optical-computing-to-the-nano-scale
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New research in an area called plasmonics has raised hopes for all sorts of seemingly implausible inventions, like cancer-killing nanotubes and mobile phones printed into t-shirts. It’s yet another breakthrough we can chalk up to carbon nanotubes and their sister material graphene, which have allowed researchers to replicate the functions of a laser on a much smaller scale than boring old light could ever allow.
One of the biggest problems with using light for industry is that it does not scale. Light of a particular color has a set wavelength, and that wavelength remains static regardless of the size of the generator; the green light of a pocket-sized laser pointer can have the same wavelength as that produced by a building-sized space-laser
This has the big advantage of providing astronomers with sensible optical information about the rest of the universe, but it also places a hard limit on miniaturization of optical devices. At scales smaller than about half the wavelength of the light being created, it’s impossible to do useful optical work. For reference, visible light runs from about 400 to about 700 nanometers in wavelength, meaning light in that range is dozens of times fatter than the scale of modern transistors.
One proposed solution to this problem is called Surface Plasmon Amplification by Stimulated Emission of Radiation, or a “spaser.” Spasers are generally referred to as nano-scale lasers, though the two technologies seem to have few similarities. Spasers basically trade photons for resonating electrons, sending optical signals called surface plasmons down the a physical substrate (thus, the field is called plasmonics). This differs from electrical conductivity in that when these surface plasmons reach their destination at the other end of the spaser, they behave like photons of light in every way that matters to a computer engineer.
Until now, the only appropriate substrate for a spaser has been bunches of quantum dots or nanoparticles of precious metal. Graphene, however, has the electrical and optical properties needed for a spaser, along with the added bonus of being strong enough for use in the real world. Graphene is an almost theoretically small substance, just a single atom thick in its purest form; this is one of the smallest sorts of computing possible.
Read Full Article: www.extremetech.com/extreme/180728-graphene-spaser-brings-optical-computing-to-the-nano-scale
.....