Yorktown Heights, NY – Mar 2010: IBM (NYSE: IBM) scientists today unveiled a significant step towards replacing electrical signals that communicate via copper wires between computer chips with tiny silicon circuits that communicate using pulses of light. As reported in the recent issue of the scientific journal Nature, this is an important advancement in changing the way computer chips talk to each other.
The device, called a nanophotonic avalanche photodetector, is the fastest of its kind and could enable breakthroughs in energy-efficient computing that can have significant implications for the future of electronics.
Dr. Solomon Assefa joined the IBM Thomas J. Watson Research Center in 2004. His research interests include Si nanophotonics integration with CMOS for optical communications, ultra-compact and highly efficient photodetectors, avalanche amplification, slow-light engineering for buffering application, low-power optical switches, and electrically-activated photonic-crystal devices for low-power switches/modulators and novel applications including biosensing. He has also explored magnetic random access memory (MRAM) and spin-torque memory device integration.
He received a B.S. degree in physics, as well as B.S. and M.S. degrees in electrical engineering and computer science (EECS) in 2001 from MIT. Then, he received a Ph.D. degree from MIT in June 2004 for his research on novel passive and active photonic-crystal devices on III–V and Si-based platforms. He was born in Addis Ababa, Ethiopia.
The IBM device explores the “avalanche effect” in Germanium, a material currently used in production of microprocessor chips. Analogous to a snow avalanche on a steep mountain slope, an incoming light pulse initially frees just a few charge carriers which in turn free others until the original signal is amplified many times. Conventional avalanche photodetectors are not able to detect fast optical signals because the avalanche builds slowly. Read the rest of this entry »
