Into the blue

摘要

If the 20th is the century of electronics, the 21st will be that of light. More and more, computers and communications are relying on light to send, store and process information. Devices that work with light are much faster, and can store more data, than those in which electrons do the legwork. But these developments have been hampered by the difficulties in generating the full spectrum of colours. The miniaturised lasers and light-emitting diodes (LEDs) needed to push the optoelectronics revolution forward have long been able to offer red, yellow and, at a push, green light. But the real gold lies at the blue end of the rainbow, and for decades it has remained out of reach.