液晶空间光调制器的纯相位调制特性研究

Research of the phase-only modulation characterization of a liquid crystal spatial light modulator

介绍了液晶空间光调制器的纯相位调制原理,采用泰曼-格林干涉系统对液晶纯相位特性进测试。针对BNS(Boulder Nonlinear Systems)公司的专利产品-256256像素纯相位空间光调制器的相位与电压(灰度)的响应曲线。给出了对任意图形进行相位恢复的优化算法流程,利用纯相位调制方法对光束进行方向和强度的快速程序控制。设计了实验装置,实际产生了二维任意衍射图形,图形产生时间小于200 ms。本研究对空间目标进行扫描跟踪,具有精确、响应快、无机械惰性等特点,在激光寻的、制导以及多目标威胁预警和反击中有着重要的研究价值。

The principle of phase-only modulation of a liquid crystal spatial light modulator（SLM） was introduced,and its phase characteristics were measured by a Twyman-Green interferometer system. The response curves of phase and voltage of the SLM with 256256 pixels patented by Boulder Nonlinear Systems （BNS） were measured. The program to retrieve the phases of an arbitrary intensity pattern was developed with an optimal algorithm. With the phase-only modulation method, the directions and intensities of laser beams could be controlled by the program easily. An experimental set-up was constructed to generate arbitrary 2-D diffractive pattern with generating pattern time in less than 200 ms. This experimental study is of value in the fields of multi-object tracing, laser guiding and multi-object defense.