光折变晶体中的稳态光扇

STEADY STATE BEAM FANNING IN PHOTOREFRACTIVE CRYSTALS

指出在高增益的光折变晶体内光束自身的多波混合是光扇形成的一个可能起因．通过光束自身的多波耦合作用，光能从低空间频率成分转移至高频成分上，从而形成宽角分布的扇形轮廓，所以放大噪声和放大光束中高频成分在光扇效应中都起重要的作用．

It is shown that multiwave mixing of the beam itself in high gain photorefractive crystals is also a possible cause of beam fanning. Through the multiwave coupling of the beam itself the power can asymmetrically transfer from low to high spatial frequencies. This leads to a broad angled profile of light. Thus amplified noise and amplified spatial frequencies of the beam both play an important role in producing the fanning effect.