Patent ID: 8013359

Claim:
An optically controlled power switching device for controllably switching power, the optically controlled power switching device comprising: a pair of terminals for the power to be switched; an optically controlled component for transmitting a control signal, the optically controlled component comprising a semiconducting carbon nanotube through which the control signal passes, the carbon nanotube responding to an optically generated charge near a wall of the nanotube to change its conductivity to control the control signal, wherein the optically controlled component further comprises a photosensitive element which responds to the optical signal by emitting electrons, the photosensitive element comprising a compound semiconductor that absorbs light and creates an electron-hole pair and being located such that the carbon nanotube is exposed to the electrons; and a power-switching component comprising either a conventional semiconductor or a wide-bandgap semiconductor element connected between the pair of terminals, the power-switching component being connected to receive the control signal from the optically controlled component to control a conductivity of the wide-bandgap semiconductor element to the power in accordance with the control signal received from the optically controlled component.