arXivDaily arXiv每日学术速递 周一至周五更新
arXiv周末暂无论文更新,休息一下吧,周末愉快~~
arXiv 1905.12902physics.optics
收藏

液晶基空间光调制器边缘场效应的精确模拟

Accurate modeling of the fringing field effect in liquid crystal based spatial light modulators

Simon Moser

摘要:

基于液晶的空间光调制器由于其以非常高的空间分辨率连续调制光场的相位的能力而广泛用于应用光学中。这些器件中的一个常见问题是像素串扰,也称为边缘场效应,其导致这些器件的响应偏离理想行为。这种边缘效应降低了空间光调制器的性能,并且被示出为引起正衍射级和负衍射级之间的衍射效率的不对称。我们使用模拟的导演分布再现二元和闪耀光栅的衍射效率测量。为了克服这些性能上的限制,利用对液晶层中指向矢分布的模拟来开发一种快速精确的模型来计算空间光调制器的相位响应。为了补偿边缘场效应,我们在相位恢复算法中实现了该模型,并计算了对应于规则光斑图案的相位轮廓作为一般示例。与不考虑边缘场效应的计算相比,这种方法能够显著提高光斑均匀性。此外,模拟和测量了不同取向的空间光调制器的各种简单的相位图案的偏振转换效率。我们发现,对于取向层上的液晶分子位于光束入射平面内的设置,偏振转换具有最小的影响。

英文摘要:

Liquid crystal based spatial light modulators are widely used in applied optics due to their ability to continuously modulate the phase of a light field with very high spatial resolution. A common problem in these devices is the pixel crosstalk, also called the fringing field effect, which causes the response of these devices to deviate from the ideal behavior. This fringing effect decreases the performance of the spatial light modulator and is shown to cause an asymmetry in the diffraction efficiency between positive and negative diffraction orders. We use simulations of the director distribution to reproduce diffraction efficiency measurements of binary and blazed gratings. To overcome these limitations in performance, the simulations of the director distribution in the liquid crystal layer are used to develop a fast and precise model to compute the phase response of the spatial light modulator. To compensate the fringing field effect, we implement this model in phase retrieval algorithms and calculate the phase profile corresponding to a regular spot pattern as a generic example. With this method, we are able to increase the spot uniformity significantly compared to a calculation without considering the fringing field effect. Additionally, polarization conversion efficiencies of various simple phase patterns are simulated and measured for different orientations of the spatial light modulator. We found that the polarization conversion has the the smallest effect for a setup in which the liquid crystal molecules at the alignment layer lie in the plane of incidence of the light beam.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑