液晶空间光调制器通过改变驱动电压强度控制液晶分子排布实现对光的调制。紫外区域可用的液晶空间光调制器随光聚合式3D打印等应用的兴起，重要性日益显现。然而绝大多数液晶材料都是有机物，在紫外波段存在光吸收和光反应。为了拓宽液晶材料的应用波段，本文通过选择在应用波段不发生紫外吸收和光反应的官能团，设计了一类可在325~400 nm波段应用不发生光吸收和光反应的液晶材料，并对液晶材料的紫外-可见光光谱进行仿真以验证设计的合理性。将耐紫外液晶化合物配置成混合液晶材料后与常见的两种混合液晶材料的紫外稳定性进行比较。在经过120 min的325 nm紫外光源的辐照后，液晶材料的吸光度和相变温度几乎不变，双折射率变化0.04%，阈值电压变化1.39%，响应时间变化0.32%。

Multi-channel detection is an effective way to improve data throughput of spectral-domain optical coherence tomography (SDOCT). However, current multi-channel OCT requires multiple detectors, which increases the complexity and cost of the system. We propose a novel multi-channel detection design based on a single spectrometer. Each camera pixel receives interferometric spectral signals from all the channels but with a spectral shift between two channels. This design effectively broadens the spectral bandwidth of each pixel, which reduces relative intensity noise (RIN) by √M times with M being the number of channels. We theoretically analyzed the noise of the proposed design under two cases: shot-noise limited and electrical noise or RIN limited. We show both theoretically and experimentally that this design can effectively improve the sensitivity, especially for electrical noise or RIN-dominated systems.

在显微成像领域中，高成像质量图像的获取与良好的照明方式息息相关。传统显微镜使用聚光透镜来提供均匀强度的照明，调节聚光透镜的光阑匹配不同放大倍率的物镜。然而无色生物细胞的光学吸收系数低，在传统显微镜下难以观测到其细节信息。为了突破传统显微镜的成像功能，本文设计了一种可调控的显微镜聚光镜模块，通过将小型扭曲液晶器件嵌入聚光透镜的后焦面处，调控液晶器件的对光的透过效果可以实现明场成像以及差分相衬成像。系统由一款商用显微镜改装而成，液晶器件尺寸为22 mm×18 mm，实现了系统的高度集成化。通过实验验证了系统的成像性能，实现了对微凸透镜样品的定量相位重建，实验与理论曲线的互相关系数达到0.994 9，并且通过胚胎干细胞的重建展示了系统在实际应用中的效果。

相位差技术可以直接利用两幅或多幅图像的强度信息，重构出波前相位信息和目标清晰图像，具有光路简单、成本较低、适用于扩展目标等优点，在望远镜的系统像差检测和目标图像重建方面得到了大量应用。相位差波前探测的关键在于求解非线性代价函数的最优化问题，需要避免陷入局部极值并降低计算时间，才能满足动态变化波前实时探测的需求。同时在重建目标清晰图像时，通常需要做正则化和去噪处理，来提高重建图像的质量。本文主要介绍相位差技术的基本原理，以及近年来的研究进展，并对该技术未来的发展进行了展望。

We report holographic fabrication of nanoporous distributed Bragg reflector (DBR) films with periodic nanoscale porosity via a single-prism conuration. The nanoporous DBR films result from the phase separation in a material recipe, which consists of a polymerizable acrylate monomer and nonreactive volatile solvent. By changing the interfering angle of two laser beams, we achieve the nanoporous DBR films with highly reflective red, green, and blue colors. The reflection band of the nanoporous DBR films can be tuned by further filling different liquids into the pores inside the films, resulting in the color change accordingly. Experimental results show that such kinds of nanoporous DBR films could be potentially useful for many applications, such as color filters and refractive index sensors.