Ulusoy Erdem, Onural Levent, Ozaktas Haldun M
Department of Electrical and Electronics Engineering, Bilkent University, Ankara, Turkey.
J Opt Soc Am A Opt Image Sci Vis. 2011 Nov 1;28(11):2310-21. doi: 10.1364/JOSAA.28.002310.
Imperfections and nonrobust behavior of practical multilevel spatial light modulators (SLMs) degrade the performance of many proposed full-complex amplitude modulation schemes. We consider the use of more robust binary SLMs for this purpose. We propose a generic method, by which, out of K binary (or 1 bit) SLMs of size M×N, we effectively create a new 2(K)-level (or K bit) SLM of size M×N. The method is a generalization of the well-known concepts of bit plane representation and decomposition for ordinary gray scale digital images and relies on forming a properly weighted superposition of binary SLMs. When K is sufficiently large, the effective SLM can be regarded as a full-complex one. Our method is as efficient as possible from an information theoretical perspective. A 4f system is discussed as a possible optical implementation. This 4f system also provides a means for eliminating the undesirable higher diffraction orders. The components of the 4f system can easily be customized for different production technologies.
实际的多级空间光调制器（SLM）存在的缺陷和非稳健行为会降低许多已提出的全复振幅调制方案的性能。为此，我们考虑使用更稳健的二进制SLM。我们提出了一种通用方法，通过该方法，在K个尺寸为M×N的二进制（或1比特）SLM中，我们有效地创建了一个新的尺寸为M×N的2(K)级（或K比特）SLM。该方法是普通灰度数字图像的位平面表示和分解这一著名概念的推广，并且依赖于形成二进制SLM的适当加权叠加。当K足够大时，有效的SLM可被视为全复SLM。从信息理论的角度来看，我们的方法尽可能高效。讨论了一种作为可能的光学实现的4f系统。该4f系统还提供了一种消除不需要的高阶衍射的方法。4f系统的组件可以很容易地针对不同的生产技术进行定制。
