Enhanced two-beam mixing gain in photorefractive GaAs using alternating electric fields

Abstract
Enhanced two-beam mixing amplification at a wavelength of 1.06 μm obtained by using sinusoidal electrical fields at 7.7 MHz is reported. The peak measured gains are comparable with dc field enhanced gain but with smaller rms fields. At grating wavelengths >3 μm the ac enhanced gain is considerably higher than the dc enhanced gain. Uniform alternating electric fields are much easier to establish inside the material and result in a much more stable output than dc fields.