Lin Hui-Zu, Liu Wei-Tao, Sun Shuai, Du Long-Kun
Appl Opt. 2021 Feb 20;60(6):1623-1628. doi: 10.1364/AO.416101.
A pulsed pseudo-thermal light source obtained using a rotating ground glass disk, spatial light modulator, or digital micromirror device is widely used in a ghost imaging (GI) lidar system. The property of the pulsed pseudothermal light field determines the reconstruction quality of the image in the GI lidar system, which depends on the pulse extinction ratio (PER) and pulse duty ratio. In this paper, pseudo-thermal light fields obtained at different pulse characteristics are given, taking into account the influence of the exposure time of the charge-coupled device (CCD) camera. The statistical distribution, contrast, and normalized intensity correlated function of the pseudo-thermal light field at different pulse characteristics are analyzed quantitatively for what we believe is the first time. Then the peak signal-to-noise ratio of the reconstructed image using a GI algorithm and a differential ghost imaging (DGI) algorithm is numerically simulated. The simulation results demonstrate that the PSNR decreases as the PER decreases, which is affected by the pulse duty ratio and the CCD exposure time. The deterioration of the reconstruction quality can be reduced by using a DGI algorithm or by shorting the exposure time of the CCD in the GI lidar system.
使用旋转毛玻璃盘、空间光调制器或数字微镜器件获得的脉冲伪热光源广泛应用于鬼成像（GI）激光雷达系统。脉冲伪热光场的特性决定了GI激光雷达系统中图像的重建质量，这取决于脉冲消光比（PER）和脉冲占空比。本文给出了考虑电荷耦合器件（CCD）相机曝光时间影响下不同脉冲特性的伪热光场。首次定量分析了不同脉冲特性下伪热光场的统计分布、对比度和归一化强度相关函数。然后对使用GI算法和差分鬼成像（DGI）算法重建图像的峰值信噪比进行了数值模拟。模拟结果表明，随着PER降低，峰值信噪比降低，这受到脉冲占空比和CCD曝光时间的影响。在GI激光雷达系统中，使用DGI算法或缩短CCD的曝光时间可以减少重建质量的恶化。
