Now, computing at blinding speed?

In an important step in the new world of optical communication and computing, physicists claim to have discovered a new way to use a gallium arsenide nanodevice as a signal processor at 'terahertz' speeds.

Gallium arsenide, a compound of the elements gallium and arsenic, is basically a semiconductor used in manufacture of devices like field-effect transistors.

Existing communications and computer architecture are increasingly being limited by pedestrian speed of electrons moving through wires and the future of highspeed communication and computing is in optics.

The Holy Grail of results would be 'wireless interconnecting' which operates at speeds 100 to 1,000 times faster than current technology, say the scientists from the US and Germany.

The new discovery 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.

Lead scientist Prof Yun-shik Lee of Oregon State University said: "Optical communication uses the extraordinary speed of light as the signal, but right now it's still controlled and limited by electrical signalling at the end.

"Electrons and wires are too slow, they're a bottleneck. The future is in optical switching, in which wires are replaced by emitters and detectors that can function at terahertz speeds."

The gallium arsenide devices used in this research can do that, the scientists claimed. "This could be very important. We were able to manipulate and observe the quantum system, basically create a strong response and the first building block of optical signal processing," Lee said.