24 April 2007
One of science’s longest-sought devices – an ‘optical memory’ that stores digital information as light – might soon be a possibility, thanks to funding of over €1 million from the European Commission.
The IOLOS project, led by Dr Siyuan Yu in the Department of Electrical and Electronic Engineering, will develop integrated optical logic and memory devices based on a semiconductor ring laser. The team will work on the principle that light will encircle an SRL, emitting a laser beam in only one of two directions – clockwise or counter-clockwise. When looking at output from one direction you would either see ‘light’ or ‘dark’, representing ‘0’ or ‘1’ in a digital system.
Provided energy is supplied to the device the recirculation is endless, much like a toy racing car going around its track for as long as the battery has power. The device can therefore remember its state as long as power supply to the SRL is not interrupted. To set the direction of the recirculation, a beam of light needs to be launched in that direction to begin with, very much like writing a ‘1’ or ‘0’ into a computer memory.
Dr Siyuan Yu, commenting on the project, said: “By making the SRL really small, we aim to develop a practical technology that may one day provide optical memories operating just like electronic memories.”