讨论了在波长不同的两单色激光束作用下,三次非线性光学介质折射率感应变化的共振增强特性。分别就双光子和频共振和双光子差频共振两种情况,导出了介质折射率非线性变化量的表示式;在实验上观察到由双光束差频喇曼共振作用导致的感应自聚焦现象,与理论结论相符合。

Resonance enhanced refractive-index change induced by two incident beams of different frequencies is discussed. The expressions of the coupled nonlinear refractive-index change are given for the sum-frequency and difference-frequency two-photon resonance conditions. Some experimental results of calcite, fused quartz fibre and benzene samples are discussed briefly.