‘Terahertz’ speed signal processor an important step for optical computing
By Darren Quick
July 20, 2010
It’s a sign of the times when the speed of electrons moving through wires is seen as pedestrian, but that’s increasingly the case as technology moves towards the new world of optical communication and computing. Optical communication systems that use the speed of light as the signal are still controlled and limited by electrical signaling at the end. But physicists have now discovered a way to use a gallium arsenide nanodevice as a signal processor at “terahertz” speeds that could help end the bottleneck.
The new discovery, made by researchers at Oregon State University (OSU), the University of Iowa and Philipps University in Germany, has identified a way in which nanoscale devices based on gallium arsenide can respond to strong terahertz pulses for an extremely short period, controlling the electrical signal in a semiconductor. The devices can be used as optical switches, replacing wires with emitters and detectors that can function at terahertz speeds.
Yun-shik Lee, an associate professor in the OSU Department of Physics, says the first applications of this type of technology would probably be in optical communications of almost any type – video, audio or others. However, the ultimate application could be quantum computing, in which computers would be orders of magnitude faster than they are now, working with a different physical and logic basis, not even using conventional transistors. Among other uses, Lee says their extraordinary speeds would make them extremely valuable for secure codes and communications.
“This could be very important,” Lee said. “We were able to manipulate and observe the quantum system, basically create a strong response and the first building block of optical signal processing.”
The team’s research appears in the journal, Solid State Electronics.