All Optical Switching

All optical switching (AOS) is one goal of the next generation of photonics research which may make possible the all optical computer. AOS means that an optical device can be used as a switch. One beam of light (the control beam) is directed on a surface plasmon whose characteristics are altered which in turn affects a second beam of light (the signal beam). This means the creation of a photonic transistor that will be able to operate at hundreds of thousands times the speed of electronic systems.

see Wikipedia Photonic Computing