纯相位空间光调制器实现振幅调制的技术研究

Research on using phase-only spatial light modulator to realize amplitude modulation

纯相位空间光调制器能够方便地模拟各种相位型光学元件,但不能直接模拟振幅型元件。使用两种方法,即棋盘相格法和闪耀光栅法,把由这两种方法生成的计算全息图加载到纯相位空间光调制器上,通过搭建的光束变换系统进行实验验证。实验结果表明,棋盘相格法和闪耀光栅法都能很好地实现振幅调制,用闪耀光栅法生成的叉状振幅光栅,给拉盖尔-高斯光束的合束带来了一种新的方法。

Spatial light modulator（SLM）with pure phase can easily simulate a variety of phase diffraction elements,but phase-only SLM cannot simulate amplitude diffraction elements directly.Checkerboard method and blazed grating method are described to achieve amplitude modulation using phase-only SLM.A beam transformation system is built to demonstrate these methods.Experimental results show that the checkerboard method and blazed grating method can achieve excellent amplitude modulation using SLM with pure phase,which increase the range of applications of phase-only SLM.A new approach is also proposed to combine two Laguerre-Gaussian beams by a forked grating generated by the blazed gratings method.