LIGHT WORK: Eight lasers constructed from inexpensive silicon
reside in this chip made by Intel. The coherent light beams
could lead to ultrafast computer circuitry that transmits data
optically. Image: PAUL SAKUMA AP Photo Scientists have long
sought to build lasers from silicon. Such an advance would
enable engineers to incorporate both electronic and optical
devices onto cheap silicon chips rather than being compelled to
employ costly-to-make lasers based on "exotic" semiconductor
materials such as gallium arsenide or indium phosphide. Silicon
lasers could lead to affordable light-based systems that harness
photons instead of electrons to shuttle huge amounts of data
swiftly--at multigigabit-per-second rates. Two research groups,
one at the University of California at Los Angeles and the other
at Intel Corporation, have recently reported success in making
silicon emit continuous laser light. This much anticipated feat
came despite silicon's dogged resistance to serving as a lasing
medium. In a good lasing