Abstract

We report an order-of-magnitude enhancement of the photorefractive effect on picosecond time scales in undoped CdTe, which we attribute to an overshoot in the photorefractive space-charge field related to hot-carrier transport on these time scales. Because there are no mid-gap levels in our undoped sample, our studies are remarkable in that the space-charge field associated with the photorefractive effect is the Dember field between mobile electron-hole pairs produced by two-photon absorption, which decays completely by ambipolar diffusion (~100 ps).

© 1991 Optical Society of America