New optical device could lead to faster, cooler computers
08 Apr 2014
Researchers have developed an optical device that could lead to new and more powerful computers that run faster and cooler. Scientists at Washington University in St Louis have developed an essential component of new computers that would run on light.
IANS quoted Lan Yang, an associate professor of electrical and systems engineering at Washington University as saying the researchers believed that their discovery would benefit many other fields involving electronics, acoustics, plasmonics and meta-materials.
The team built an optical diode pairing doughnut-shaped optical resonators – one with gain and the other with loss – on a silicon chip.
According to lead author Bo Peng from Yang's team, the diode was capable of completely eliminating light transmission in one direction and greatly enhancing light transmission in the other.
Peng added, coupling of so-called loss and gain devices using PT (parity-time)-symmetry could enable such advances as cloaking devices, stronger lasers that needed less input power, and perhaps detectors that could 'see' a single atom.
The optical diode comprised two micro-resonators positioned so that light could flow from one to the other. One device was the ''lossy'' silica resonator, while the other incorporated the chemical element erbium into the silica structure for gain.
In an optical diode, the light input in one direction is transmitted while the light input in the opposite direction is blocked, Reuters reported.
The new optical diode, designed by Yang and her collaborators from Washington University is made from parity-time (PT) symmetric micro-resonators in which loss of one of the resonators is balanced by the gain in the other.
Breaking the PT-symmetry, by tuning the coupling strength between the resonators, creates strong field localisation and allows nonlinearity-based one-way transmission for light.
An electrical diode eliminates electricity back-flow along a wire allowing protection to crucial parts of an electronic circuit or processor; an optical diode does the same thing with light.
