Paniccia's team came up with an answer that was both brilliant and, for those familiar with silicon technology, conceptually simple. Etched into the Intel laser chip was a silicon waveguide channel in which light bounced back and forth, gaining in intensity. The researchers implanted electrodes on both sides of the channel. When they turned on a voltage between the electrodes, it created an electric field that herded the negatively charged electrons toward the positively charged electrode, effectively sweeping them out of the way. As a result, the photons were able to build up unhampered, until they produced a continuous laser beam.
Robert Service, "Intel's Breakthrough," MIT Technology Review, July 2005
