利用空间光调制器的衍射特性提高VLC输出相关峰值

Enhancing correlation peak value in VLC by diffraction characteristic of SLM

Vander Luget相关器(VLC)中,由于空间光调制器(SLM)像素的周期性结构,在匹配滤波面上会产生目标图像的多级衍射谱。为了提高VLC输出的相关峰值,在不同级衍射谱处同时加载了匹配滤波器进行匹配滤波。理论分析表明,各级谱输出的相关点在输出面上位置相同,相干叠加的结果会使输出相关峰值提高。实验结果表明,和只对0级谱进行匹配滤波的情况相比,对目标图像的多级衍射谱同时进行匹配滤波可使平均输出相关峰值提高约32%,该方法能有效提高VLC的输出相关峰值。

The multilevel diffraction spectrum of target image on the filtering plane produced by the periodic structure of Space Light Modulator（SLM） in Vander Luget Correlator（VLC） was obtained. In order to increase output correlation peak value, matched filters can be loaded at the positions of different diffraction spectra on the filtering SLM at the same time to perform matched filtering of multi level diffraction spectra. Theoretical analysis results indicate the correlation spots from different diffraction spectrum outputs are at the same position of the output plane, and the correlation peak value is improved with coherent superposition of multilevel correlation spots. The experimental results show that the mean output correlation peak value by performing matched filtering for multilevel diffraction spectra of target image has increased about 32% than that of zerolevel spectrum. The output correlation peak value can be effectively increased using this method.