液晶稳态和瞬态多波混频与非线性光学特性

在掺杂（～3%重量比）碳纳米管和光敏取向基团的向列态液晶薄膜（5μm厚）中，在使用Ar⁺(514.5nm)为激发光做前向多波混频实验时，观察到7级的自衍射和探测光He-N e(632.8nm )的多级衍射均呈多环状结构.高斯光束中心处的光致非线性折射率系数δn～0.8. Ar⁺ (514.5nm)连续光形成光栅的时间和弛豫时间都与写入光的偏振态强烈相关.在使用Nd :YAG（532 nm）为激发光时，光栅的弛豫时间～200ms量级，且探测光He-Ne(632.8nm)的o光和e光所探 测到的动力学响应曲线是不同的. 关键词： 瞬态 稳态 多波混频 液晶

Transient and steady-state multi-wave nonlinear optical properties of liquid crystal film

Transient and steady-state multi-wave mixing experiments are carried out on the novel azo＋c-tube liquid crystal sample. The shape of the diffracted multi-wave consists of rings under Ar^＋（514.5nm） laser pump light, and th e nonlinear refractive index is n～0.8. Using different polarization states of the pump laser light field, different reorientation models of liquid crystal molecules ar e observed. On the other hand, a Nd:YAG（532nm）pulsed laser is used, polarizati on holographic gratings are detected by a He-Ne (632.8nm)laser beam. Different p rocesses of liquid crystal molecular reorientation are also detected using the o -light beam and e-light beam of a He-Ne (632.8nm)laser.