基于硅基液晶实现激光投影显示系统匀光整形和散斑抑制

发布时间：2018-05-02 05:02

本文选题：激光光学 + 衍射光学　；参考：《中国激光》2016年12期

【摘要】：激光投影显示通常需要解决光束整形匀化和散斑抑制的问题。基于此,提出利用硅基液晶(LCoS)空间光调制器(SLM)同时解决上述问题的方法。利用衍射光学元件(DOE)精细化设计思想设计所需整形DOE的相位分布,可以同时较好地控制采样点与采样点以外的光场强度分布,将圆形高斯分布照明激光束整形成平顶矩形光场;在不同的初始相位条件下,设计得到的多幅DOE生成具有相同强度分布、不同相位分布的衍射图样。当SLM依次调制出这些衍射图样,通过时间积分将这些衍射图样相叠加,不仅可以进一步提高光斑均匀性,同时还可以抑制散斑。仿真结果表明,通过叠加16幅衍射图样,该方法可使照明光斑均匀性从74%提高到92.57%,屏幕上图样散斑对比度由0.991减小为0.2508。该方法稳定性高,能耗低,且所用器件尺寸小,为微投影显示结构设计提供了有益参考。
[Abstract]:Laser projection display usually needs to solve the problems of beam shaping homogenization and speckle suppression. Based on this, a method is proposed to solve the above problems simultaneously by using the spatial light modulator (SLM) of silicon based liquid crystal (LCoS). The phase distribution of the shaping DOE needed by the fine design of the diffraction optical element doe can control the intensity distribution of the light field outside the sampling point and the sampling point at the same time, and the circular Gao Si distribution illumination laser beam can be shaped into a flat-top rectangular light field. Under different initial phase conditions, the diffraction patterns with the same intensity distribution and different phase distribution are obtained by the design of multiple DOE. When SLM modulates these diffraction patterns in turn, the diffraction patterns are superposed by time integral, which can not only further improve the uniformity of light spots, but also suppress the speckle. The simulation results show that by adding 16 diffraction patterns, the uniformity of illumination spot can be improved from 74% to 92.57%, and the speckle contrast on screen can be reduced from 0.991 to 0.2508. This method has the advantages of high stability, low energy consumption and small device size, which provides a useful reference for the design of microprojection display structure.
【作者单位】：中国科学院长春光学精密机械与物理研究所超精密光学工程研究中心;中国科学院大学;
【分类号】：O436

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