数字离轴全息实验系统及其零级像分析

Experimental System of Digital Off-Axis Holography and Analysis of Zero-Order Image

针对数字全息术中记录介质分辨率制约物参光的最大夹角给实验系统搭建带来的问题,提出一种数字离轴全息记录系统.该系统是将低频全息衍射光栅作为分光元件引入数字全息系统,利用光栅衍射的0级和+1/-1级形成离轴全息记录光路,同时对再现像中零级进行了理论分析,并进行实验研究.实验结果证明了该系统的可行性,并且具有光路系统简单、操作容易等特点.

In digital holography, the limited spatial resolution of the charge coupled device （CCD） imposes a limit on the angle between the object beam and the reference beam, which brings about the difficulties in setting up the experimental system. For this reason, a simple hologram recording system of digital off-axis holography was presented. Holographic diffraction grating of low spatial frequency was introduced to digital holography and employed as a beam splitter, and all off-axis holography system was formed using interference of the ＋ 1/- 1 order diffraction wave and the zero-order wave, which were generated by grating diffraction. The zero-order diffraction in the reconstructed image of off-axis digital holography was analyzed theoretically, and validated by experiments. The experimental results show that the system presented is feasible, simple in optical structure and easy in operation.