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    Method of producing an optical wave with a predetermined optical function
    5.
    发明授权
    Method of producing an optical wave with a predetermined optical function 失效
    具有预定光学功能的光波的制造方法

    公开(公告)号：US5363186A

    公开(公告)日：1994-11-08

    申请号：US192475

    申请日：1994-01-27

    申请人： Robert W. Cohn ,  Minhua Liang

    发明人： Robert W. Cohn ,  Minhua Liang

    IPC分类号： G02B26/06 ,  G01C3/08

    CPC分类号： G02B26/06 ,  G03H1/08 ,  G03H2225/24 ,  G03H2225/32

    摘要： A five step method is used to produce an optical wave. The first step is to pick the desired far field pattern of the diffractive optical wave. The second step entails transforming the desired far field pattern to the desired source using a fast fourier transform (FFT). In the third step we use the formula exp[j.phi..sub.i (.sigma..sub.i)]=A.sub.i exp(j.phi..sub.i) to find the standard deviation .sigma..sub.i for each pixel i that produces the desired/average amplitude. Next, we use a pseudo-random number generator to select phases .phi..sub.i from distributions of standard deviation .sigma..sub.i for each pixel. Finally, we check the solution with the FFT and our analyses of performance.

    摘要翻译： 使用五步法来产生光波。 第一步是选择衍射光波的期望的远场图案。 第二步需要使用快速傅里叶变换（FFT）将期望的远场图案变换为期望的源。 在第三步中，我们使用公式exp [j phi i（sigma i）] =＆upbar＆Aiexp（j phi i）找到产生所需/平均幅度的每个像素i的标准偏差σi。 接下来，我们使用伪随机数生成器从每个像素的标准偏差σi的分布中选择相位phi i。 最后，我们使用FFT和性能分析来检查解决方案。

    Method and apparatus for adaptive real-time optical correlation using phase-only spatial light modulators and interferometric detection
    7.
    发明授权
    Method and apparatus for adaptive real-time optical correlation using phase-only spatial light modulators and interferometric detection 失效
    使用相位空间光调制器和干涉测量检测的自适应实时光学相关方法和装置

    公开(公告)号：US5276636A

    公开(公告)日：1994-01-04

    申请号：US950633

    申请日：1992-09-14

    申请人： Robert W. Cohn

    发明人： Robert W. Cohn

    IPC分类号： G06E3/00

    CPC分类号： G06E3/005

    摘要： A video-rate correlator constructed with a phase-only spatial light modulator and video camera. The phases of the Fourier spectra of a test and reference image are measured by real-time fringe scanning interferometry. The two phase images are then electronically subtracted. The optical Fourier transform of this difference produces the phase-only correlation response. This correlator is real-time adaptive, in that it uses live imagery, and neither the test or reference images need any preprocessing off-line. Especially small optical layouts, which also efficiently use light for correlation, can be configured through the use of specific embodiments, which use only a single phase-only spatial light modulator and Fourier transform lens.

    摘要翻译： 一个视频速率相关器，用相位空间光调制器和摄像机构成。 通过实时条纹扫描干涉测量法测量测试和参考图像的傅里叶谱的相位。 然后电子减去两相图像。 该差异的光学傅里叶变换产生仅相位相关响应。 该相关器是实时自适应的，因为它使用实时图像，测试或参考图像都不需要离线进行任何预处理。 可以通过使用仅使用单个相位相对空间光调制器和傅立叶变换透镜的特定实施例来配置也有效地使用光进行相关的特别小的光学布局。

    Nanolithography for multi-passband grating filters
    8.
    发明授权
    Nanolithography for multi-passband grating filters 失效
    多通道光栅滤波器的纳米光刻技术

    公开(公告)号：US06322938B1

    公开(公告)日：2001-11-27

    申请号：US09575252

    申请日：2000-05-22

    申请人： Robert W. Cohn

    发明人： Robert W. Cohn

    IPC分类号： G03F700

    CPC分类号： G02B5/1852 ,  G01Q80/00 ,  G03F7/2049 ,  H01J2237/31759 ,  Y10S977/855

    摘要： The placement accuracy and resolution of direct-write patterning tools, in particular the atomic force microscope (AFM), is considered for application to fabricating multi-passband integrated optical filters. Because of its simpler fabrication a grating structure is proposed that consists of identical stripes that are non-periodically spaced. The recently developed pseudorandom encoding method from the field of computer generated holography is modified to effectively assign analog reflectances at each point along the grating by selective withdrawal and offsetting of the stripes from a periodic spacing. An example filter designed by this method has two 1.5 nm bandwidth passbands and −23 dB of rejection for lightly coupled stripes. As with single band filters, the passbands broaden as the coupling increases. A calculation of the coupling coefficient of stripes on a fundamental mode, slab waveguide indicate that stripes on the order of 100 nm in depth and width support low insertion loss, multipassband filtering applications at visible wavelengths. Lines of these dimensions patterned with an AFM on (110) silicon indicate the feasibility of fabricating these filters. These conclusions are specific to current AFMs that are limited to writing fields of 100 &mgr;m. Increased rejection and decreased passband widths will result from incorporating precise field-stitching into future AFMs.

    摘要翻译： 直写式图形工具，特别是原子力显微镜（AFM）的放置精度和分辨率被认为用于制造多通道集成滤光器。 由于其更简单的制造，提出了由非周期性间隔的相同条纹组成的光栅结构。 修改了最近从计算机生成的全息术领域开发的伪随机编码方法，通过选择性地从周期性间隔中取出和偏移条带来有效地分配沿着光栅的每个点处的模拟反射。 通过该方法设计的示例滤波器具有两个1.5nm带宽通带和对于轻耦合条纹的-23dB的抑制。 与单频带滤波器一样，随着耦合增加，通带变宽。 在基本模式下，条形波导的耦合系数的计算表明，在深度和宽度上100nm级的条纹支持低插入损耗，在可见波长处的多通带滤波应用。 在（110）硅上用AFM图案化的这些尺寸的线表明制造这些过滤器的可行性。 这些结论是针对当前的AFM，仅限于写作100个妈妈的领域。 通过将精确的现场缝合结合到未来的AFM中，会增加阻抗和降低通带宽度。

    Modified minimum distance criterion for blended random and nonrandom encoding
    9.
    发明授权
    Modified minimum distance criterion for blended random and nonrandom encoding 失效
    混合随机和非随机编码的修改最小距离标准

    公开(公告)号：US06275310B1

    公开(公告)日：2001-08-14

    申请号：US09575270

    申请日：2000-05-22

    申请人： Robert W. Cohn

    发明人： Robert W. Cohn

    IPC分类号： G03H108

    CPC分类号： G03H1/08 ,  G03H2001/0858

    摘要： Two pixel-oriented methods for designing Fourier transform holograms, pseudorandom encoding and minimum distance encoding when combined usually produce higher fidelity reconstructions than either method produces individually. In previous studies, minimum distance encoding was defined as the mapping from the desired complex value to the closest value produced by the modulator. This method is compared with a new minimum distance criterion in which the desired complex value is mapped to the closest value that can be realized by pseudorandom encoding. Simulations and experimental measurements using quantized phase and amplitude modulators show that the modified approach to blended encoding produces more faithful reconstructions than the previous method.

    摘要翻译： 用于设计傅里叶变换全息图，伪随机编码和最小距离编码的两个像素方向的方法通常产生比任一种方法单独产生的更高的保真度重建。 在以前的研究中，最小距离编码被定义为从所需的复数值到由调制器产生的最接近的值的映射。 将该方法与新的最小距离标准进行比较，其中期望的复数值被映射到可以通过伪随机编码实现的最接近的值。 使用量化相位和幅度调制器的模拟和实验测量显示，混合编码的修改方法比以前的方法产生更多的忠实重建。

    Extensions and improvements of method of producing an optical wave with a predetermined function
    10.
    发明授权
    Extensions and improvements of method of producing an optical wave with a predetermined function 失效
    具有预定功能的光波的制造方法的扩展和改进

    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。