Gianino P D, Woods C L
Appl Opt. 1993 Nov 10;32(32):6527-35. doi: 10.1364/AO.32.006527.
In Part I we present an approximate mathematical analysis and exact computer simulations for optical correlation in correlators having pixellated spatial light modulators with transmissive (or reflective) dead zones in both the input and filter planes. We show that the correlation amplitude consists of four terms: a true correlation plus three different types of noise terms originating from the transmissive dead zones in both spatial light modulators; we describe the role that each of these terms plays in the correlation process. We calculate peak intensity, signal-to-noise ratio, and energy throughput efficiency as a function of dead-zone area in both spatial light modulators using either phase-only or matched filters. We utilize a dc block in the filter plane for noise reduction. We also use a filter reference image smaller than the input spatial light modulator size to reduce false correlation peaks. We discuss the effects of fabricating a filter from a filter reference image whose center has been offset rom optic axis. In Part II [Appl. Opt. 32,6536 (1993)] we present a general analytical treatment of our model that can justify the simulation results of Part I. This analysis is applicable even to mixed cases of opaque and transmissive dead zones.
在第一部分中，我们针对在输入平面和滤波器平面均具有带透射（或反射）死区的像素化空间光调制器的相关器中的光学相关，给出了近似数学分析和精确计算机模拟。我们表明，相关幅度由四项组成：一个真实相关加上源自两个空间光调制器中透射死区的三种不同类型的噪声项；我们描述了这些项中的每一项在相关过程中所起的作用。我们使用纯相位滤波器或匹配滤波器，计算了作为两个空间光调制器中死区面积函数的峰值强度、信噪比和能量传输效率。我们在滤波器平面中使用一个隔直块来降低噪声。我们还使用小于输入空间光调制器尺寸的滤波器参考图像来减少虚假相关峰值。我们讨论了由中心偏离光轴的滤波器参考图像制造滤波器的影响。在第二部分[《应用光学》32,6536 (1993)]中，我们给出了对我们模型的一般分析处理，它可以证明第一部分的模拟结果是合理的。这种分析甚至适用于不透明和透射死区的混合情况。
