偶氮材料——乙基橙的光致双折射特性

Photoinduced birefringence in an azo-dye-doped polymer

将偶氮化合物乙基橙样品置于一对正交的偏振片之间,用一束激发光照射该样品,分别测量在激发光的不同强度和不同偏振方向下探测光的透射功率,研究样品的双折射特性.实验表明,透射光的饱和值和稳定值与激发光强成正比,且与激发光偏振方向有关,探测光与激发光振动方向的夹角(θ)为45°时,其值最大;若θ不太小(>10°),sin22θ与透射光的饱和值、稳定值成线性关系.同时,利用巴俾涅补偿器对样品的双折射率差进行了测量,分别得到了绿光激发前后的准确数值为1.11×10-3和3.57×10-3.

Under varying intensities and polarization of the exciting light, the photoinduced birefringence of azo dye polymer film placed between a pair of orthogonal polarizers is studied by measuring the transmitted intensity. It is concluded that the saturation and stable values of the transmitted intensity are all proportional to the intensity of the exciting light. Both values are also related to the polarization direction of the exciting light, and when the angle 0 between the polarization directions of the probe intensity and the exciting light is lager than 10 degrees, the saturation and stable values of the transmitted light are all proportional to sin(2)2 theta. In addition, the differences in birefringences of the sample were measured accurately by using a compensator and 1.11 x 10(-3) (before excitated) and 3.57 x 10(-3) (after excitated) are obtained.