一种液晶相位调制特性的测量方法

提出一种基于衍射光栅的液晶相位调制特性测量方法.该方法利用液晶构建相位分别为0和φ的二值光栅,通过傅里叶光学的方法推导衍射光栅第0级衍射光斑光强和调制相位φ之间的关系,然后实测光强和液晶驱动电压之间的对应关系来得到相位和液晶驱动电压之间的对应关系,即液晶相位光栅的相位调制特性.最后利用测量相位调制特性结果构建液晶相控阵,用光束偏转误差验证调制特性测量结果,相位测量误差小于1×10~(-3)rad.

A Method of Measure the Liquid-crystal′s Modulating Characteristic

A method to measure modulation property of liquid crystal based on diffraction grating was proposed.This method utilizes liquid-crystal to establish the binary phase gratings with the phase of 0 and φ respectively, the relation between intensity of zero-order diffraction spots and φ can be deduced by Fourier transformation, and the relation between intensity of zero-order diffraction spots and voltage of liquid crystal pole was measured by experiment.Therefore,relation between phase φ and voltage of pole liquid crystal can be achieved, that is the modulation property of this liquid crystal.Finally, the modulation property was used to creat liquid crystal phased array to steer laser beam, experimental results indicate that phase error is less than 1×10-3 rad.