The photorefractive effect in semiconductors.

The photorefractive effect in semiconductors is reviewed with special emphasis on the unique capabilities of high mobility materials compared with ferroelectric oxides. It is shown that the smaller electro-optic effect in semiconductors compared with oxides is not a serious handicap for optical information processing applications. However, the ability to tailor the spectral sensitivity range in the near infrared and the material response time from milliseconds to nanoseconds by appropriate doping is particularly advantageous in semiconductors. This paper describes the nature of the dopants and stoichiometric defects which sensitize GaAs and InP for photorefractive applications and the optimization of the photorefractive behavior for low and high speed applications is discussed.