单透镜菲涅尔计算全息显示系统中多级像和零级光的去除

为了消除多级像和零级光的干扰,提出了一种单透镜结构的系统,获得了单一无扰的再现像.使用Gerchberg-Saxton(GS)算法获得菲涅尔全息图,预先叠加倾斜平面波相位至菲涅尔全息图上,使再现像移至中央位置.用成像透镜将空间光调制器(SLM)后方的虚像成像至前方,同时在成像透镜后方放置空间滤波器,滤去多级像和零级光.调整透镜与SLM的位置可方便调整再现像的大小和位置,缩短了光学系统的长度.利用虚像的方法为基于液晶SLM的计算全息显示提供了新的思路.

Elimination of zero-order beam and multi-images in single-lens Fresnel holographic display system

In order to eliminate the interference of multi-level images and zero-order beam,a system with single-lens structure is proposed,and a single image without crosstalk is obtained.The Fresnel hologram is obtained by using Gerchberg-Saxton (GS) algorithm.The inclined plane wave phase is pre-superimposed on Fresnel hologram to move the image to a central location.The virtual imaging behind spatial light modulator(SLM) is imaged to the front using imaging lens.At the same time,the spatial filter is placed in the rear of imaging lens,and the multi-level images and zero order light are filtered.The size and position of the reconstructed image can be modified conveniently by adjusting the position of lens and SLM,and the optical system length is shortened.The method utilizing the virtual image provides a new way for calculating holographic display based on liquid crystal SLM.