Researchers have developed the first light-based microprocessor

A microprocessor that uses optical connections instead of electrical wires to shuttle data around has long been the dream of chip designers, but the attempt to fabricate one has frustrated them for years. Now a prototype described in the journal Nature offers a promising and practical approach. The electronic-optical microprocessor, developed by a group of researchers at MIT, the University of California, Berkeley, and the University of Colorado, Boulder, integrates over 70 million transistors and 850 optical components. The system uses optical fibers, transmitters, and receivers to send data between a processor chip and a memory chip. In a demo, it runs a graphics program to display and manipulate a 3-D image, a task that requires using the internal optical connections to fetch data from memory and run instructions. Optical connections can carry more data faster than electrical ones consuming the same amount of power. The data transfers in the prototype occurred at a rate of 300 gigabits per second per square millimeter, which the researchers say is 10 to 50 times the rate for a comparable off-the-shelf electronic microprocessor. That boost in bandwidth could save a lot of energy in data centers, says Chen Sun, a researcher at the University of California, Berkeley.