光折变晶体中与光强有关的二波耦合及能量转移

Intensity Dependent Energy Transfer through Two-wave Mixing in Photorefractive Crystal

用一种模型对对称入射的两束相干光在光折变晶体内的耦合即能量转移进行了分析,导出了单边入射二波耦合的信号光放大率的解析表达式。分析了对KNSBN光折变晶体的二波耦合测量结果,求得与光强有关的耦合常数值。此外,给出了信号光放大率及两束光的光强随入射光强、束比、吸收系数、饱和耦合常数及介质厚度变化的曲线。

The analytical expression for the gain of signal beam through two-wave mixing in photorefractive crystal is deduced with a simple model. The exper-imental data of two-wave mixing in KNSBN crystal are analyzed and the inten-sity-dependent coupling coustant is determined. In addition, the gain of the signal beam and the intensities of two coupling waves both inside and outside the crystal are presented in graphic forms.