Photorefractive gain in GaAs under a dc electric field

Abstract

We report the first observation of a photorefractive gain coefficient as high as 2.6 cm−1 in the undoped liquid-encapsulated Czochralski-grown GaAs crystals at 1.06 μm under a dc electric field of 13 kV/cm without using the moving grating technique. The absorption coefficient of the crystals used is 1.3 cm−1, showing that a net gain has been achieved. This measured gain coefficient is close to the predicted theoretical value.