公开(公告)号：US06248487B1

公开(公告)日：2001-06-19

申请号：US09538245

申请日：1999-04-26

申请人： Robert W. Cohn ,  Shaad Bidiwala

发明人： Robert W. Cohn ,  Shaad Bidiwala

IPC分类号： G03C500

CPC分类号： G03H1/08 ,  G02B26/0808 ,  G03H1/0244 ,  G03H1/0841 ,  G03H2240/13

摘要： Spatial light modulators (SLMs) can be amplitude-only modulated, phase-only modulated, or the pixel amplitudes can even be a function of phase. However, practical devices providing independently controllable values of phase and amplitude are not expected for some time. It has been possible to design modulation patterns for these limited range SLMs that do produce diffraction patterns similar to those possible from full complex SLMs, but hours of intensive iterative optimization usually have been required. Our approach instead develops and evaluates direct, pixel-by-pixel encoding algorithms that map the limited range modulation properties onto the entire complex plane. The advantage of these algorithms (generally recognized by the name pseudo random encoding) over iterative optimization is that designs can be performed in real-time making systems adaptable to rapidly changing situations. For laser scanning using SLMs, encoding enables multiple spots to be generated and their positions to be maintained on multiple moving targets. For correlators, a fast encoding method would provide a way to adaptively construct composite filters (capable of recognizing objects from many perspectives, or classes of objects) by linearly combining individual matched filters. For fixed pattern diffractive optical interconnects, the encoding method can lead to faster iterative optimization algorithms, as well and the devices that are suggested by the design can be affordably produced using existing microfabrication art.

摘要翻译： 空间光调制器（SLM）可以是仅幅度调制的，仅相位调制的，或者像素幅度甚至可以是相位的函数。 然而，提供独立可控的相位和幅度值的实际装置在一段时间内是预期的。 可以为这些有限范围的SLM设计调制模式，这些限制范围的SLM产生类似于全复杂SLM可能的衍射图案，但通常需要进行强化迭代优化的时间。 我们的方法是开发和评估直接的逐像素编码算法，将有限范围调制属性映射到整个复平面上。 通过迭代优化，这些算法（通常被称为伪随机编码识别）的优点在于，可以实时地执行设计，使系统适应于快速变化的情况。 对于使用SLM的激光扫描，编码使得能够生成多个点并且其位置被保持在多个移动目标上。 对于相关器，快速编码方法将提供一种通过线性组合单个匹配滤波器来自适应地构建复合滤波器（能够从多个视角或对象类别识别对象）的方法。 对于固定图案衍射光学互连，编码方法也可以导致更快的迭代优化算法，并且可以使用现有的微细加工技术可靠地制造设计所建议的器件。