Raman lasers and Intel
has created a chip containing eight continuous Raman lasers by using fairly
standard silicon processes rather than the somewhat expensive materials and
processes required for making lasers today. The lasers emit a continuous stream
of light that can then be modulated, or chopped up, into a stream of impulses
that can represent data. Cheap optical parts could not only lead to faster computers
but also to less expensive and more accurate medical equipment.
While silicon lasers likely won't enter the market for at least four to five
years, the chip should generate enthusiasm and interest in the industry. Although
manufacturers love silicon, it's typically a terrible carrier for optical data.
The laser represents the latest step in Intel's plans to adopt optical links
to connect computers, chips or eventually even subcomponents on the same chip.
It is also part of a larger effort at Intel to employ its factories to make
silicon chips that can test blood or perform mechanical tasks rather than just
calculate ones and zeros.
data on light comes with tremendous advantages. Power consumption and heat dissipation
have become a huge problem for chip designers. Photons, units of light carried
on optical fiber, generate far less heat than electrons, the signal carriers
on copper wire. Fiber strands can also handle far more data traffic, thereby
cutting down on cabling and the internal volume of computers.
The catch is that optical components are expensive to manufacture and require
exotic materials. Assembling the components into complete systems also remains
an arduous task.
A Raman laser, in some ways, is ideally suited for silicon. The Raman Effect,
discovered in 1928 by Nobel laureate Chandrasekhara Venkata Raman, roughly works
as follows: light hits a substance, causing the atoms in the substance to vibrate.
The collision causes some of the photons to gain or lose energy, resulting in
a secondary light of a different wavelength. A Raman laser essentially takes
this secondary light and amplifies it (by reflecting it and pumping energy into
the system) to emit a functional beam.
Because of its crystalline structure, silicon atoms readily vibrate when hit
with light. The Raman Effect, in fact, is 10,000 times stronger in silicon than
standard glass, which should make it far easier to amplify.