偶氮聚合物的光致各向异性研究

Photoinduced Anisotropy in an Azobenzene-Containing Polymer

研究了一种偶氮聚合物的光致各向异性,在泵浦光作用下,样品薄膜的面内有序度可以达到0.53,光致双折射在室温下可以达到10-2量级.泵浦光强对样品的各向异性有较大影响,特别是光致双折射,泵浦光强过高引起的热效应可以破坏已有的分子排序,导致双折射信号的降低.在存储应用中,为了最大限度地利用材料的各向异性,需要选择合适的泵浦光强和泵浦作用时间.

The photoinduced anisotropy of an azobenzene-containing polymer is investigated. The polymer possesses large photoinduced dichroism and birefringence（ 10-2）. Stable value of the in-planeorder parameter of 0. 53 has been achieved in this materialat room temperature. As the pump intensity increases,the saturation value of the birefringence reaches a maximum during the irradiation period. Over the optimal pump intensity,the thermal effect caused by the high intensity of the pump light can destroy the existing molecular ordering,which leads to the decrease of the birefringence signal. In storage applications,in order to maximize the use of material anisotropy,we should select the appropriate pumpintensity and pump time.