Raman lasers and Intel

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.

Carrying 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.