Wave Mixing In Photorefractive Bismuth Silicon Oxide Crystals And Its Applications

We review the conditions of high gain in wave-mixing experiments with photorefractive Bit 2Si020 crystals. These interactions are based on the recording of a moving interference pattern in the volume of the crystal ("drift" recording mode with an externally applied electric field). This technique has recently resulted in large values of the exponential gain coefficient r = 8 to 12 cm-1 for an optimized grating velocity and grating spacing. Applications to image amplification, laser beam steering, amplified phase conjugation, and self-induced optical cavities are presented.