采用表面反射方法研究块状掺偶氮苯聚合物的光致折射率改变特性及其与光强的依赖关系。实验中,使用514 nm的圆偏振Ar+激光作为抽运光,632.8 nm的He-Ne激光(s偏振)作为探测光。通过改变探测光入射角,测量样品在固定光强(0.570 W/cm2)的前向抽运光激励下表面反射率的改变量,研究样品的折射率改变特性,发现样品的光致折射率改变约为-0.0035;研究了这种效应对抽运光强度的依赖关系,发现光致折射率改变随抽运光强度增大而增大,当抽运光强为0.800 W/cm2时,折射率改变量可达10-2量级。

The characterization of photoinduced refractive index change (Δn) and the relation between Δn and the intensity of pumping beam in the azobenzene doped polymer are investigated using surface-reflection configuration in which a circularly polarized pumping beam at 514 nm and a probing beam (s-ray) at 632.8 nm are used. For a given pumping intensity (0.570 W/cm2), the surface reflectivity of the sample is measured at a series of incident angles of the probing beam, and the Δn is about -0.0035. Furthermore, the investigation shows that Δn increases with increasing the intensity of pumping beam, and Δn reaches a value of 10-2 when the intensity of pumping beam is 0.800 W/cm2.