中文摘要：

研究了平面型掺偶氮染料（DR1）向列液晶（5CB）薄膜对可见光波段的响应及在二波耦合实验中探测光（633nm）的衍射效率与记录光（488nm）偏振的关系，并进行了相应解释，得到了小角度入射条件下，记录光偏振方向平行于样品摩擦取向方向时的空间变化的介电张量。此结果适用于多数偶氮类染料，很好地解释了光致顺-反异构引起的折射率变化。

英文摘要：

The visible spectral response and the dependence of the diffraction efficiency of probe light （633 nm） on polarized pump light at a two-beam coupling in the planar Disperse Red 1 （DR1）-doped sample have been observed. An analysis is presented. A spatially varying dielectric tensor is obtained in the case of a small recording angle when the polarization direction of the recording beams is parallel to the director vector of the sample. This result may explain the index change induced by trans-cis isomerization in most of azo-dye-doped liquid crystal films.