First Germanium Laser Lasers made of silicon-compatible material
could bring optical data transmission onto computer chips Image:
David Freund/iStockphoto 10 February 2010—A laser made of
germanium may open the door to optical interconnects on computer
chips that have multiple processing cores, say researchers at
MIT, who recently demonstrated such a laser. The group, led by
Jurgen Michel, a research scientist at MIT’s Microphotonics
Center, achieved low-level lasing at room temperature with a
laser built from layers of germanium grown on a silicon wafer
and powered by pulses from a separate laser. The paper is set to
be published soon in Optics Letters. Michel envisions using such
a laser to make an optical bus, which would carry data around a
multicore microprocessor. On a chip with 64 cores, such a system
could have 40 times the power efficiency of traditional wire
connections, he estimates. And in the next few years, chips with
hundreds of cores are expected to make the concept even more
useful. Another a