玻璃与液晶非线性光学界面反射特性的研究

本文系统地研究了由玻璃与液晶构成的非线性光学界面。用一台调Q的红宝石激光器研究了由玻璃与处于各向同性液相的液晶所构成的非线性界面。在不同入射角时非线性界面由内部全反射跃变到部分透射的阈值光强与Kaplen的平面波理论计算结果相一致。在T-T_c=2.5℃条件下测量了时间分辨的非线性界面的反射率。观察到了反射率的滞后迴线。非线性界面的这种反射率的滞后迴线可以归之于液晶分子退取向的弛豫过程。用Ar⁺激光器研究了玻璃与向列相液晶所构成的非线性光学界面,观察到了由相变而产关键词：

THE REFLECTION BEHAVIORS OF NONLINEAR OPTICAL INTERFACE BETWEEN GLASS AND LIQUID CRYSTAL

The reflection behavious of nonlinear optical interface between glass and liquid crystal were studied systematically. The reflection behaviours of such interface with isotropic liquid phase was studied by using a Q-switched ruby laser. The threshold intensity of transition from TIR (tolal internal reflection) to partial transmission for different incident angle were measured at T-T_c = 2.5℃. It agrees with the plane wave theory of Kaplan. The time resolved reflection of nonlinear interface was also measured and hysteresis loop of reflectivity was observed. The hysteresis loop of reflectivity can be attributed to the deorientation relaxation processes of liquid crystal molecules. The nonlinear optical interface between glass and ne-matic liquid crystal was also studied using an Ar⁺ laser. The transition from TIR to partial transmission was observed at the intensity 700 W/cm². This transition can be attributed to thermal induced phase transition from nematic mesophase to isotropic liquid phase.