自然界光子晶体图案为生物的生存提供了独特的功能，例如变色龙使其皮肤图案颜色适应环境以进行伪装保护，头足类动物（鱿鱼、墨鱼、章鱼等）能够产生宽波长范围的结构颜色和光学图案以利于物种间的信息交流。受自然界光学图案的特殊功能启发，胆甾相液晶的图案得以开发，并在数据存贮、传感器、柔性智能器件等方面展示了潜在应用。本文综述了胆甾相液晶图案的外场刺激响应性、功能演变及其应用。首先，总结了胆甾相液晶图案的外场刺激响应性，包括光、电、热、机械力和溶剂。其次，介绍了胆甾相液晶图案的各种应用，如具有加密和解密功能的存贮器件、信息安全防伪设备、柔性可穿戴传感器和圆偏振发光系统等。最后，介绍了胆甾相液晶图案的前景和挑战。本文为构建基于胆甾相液晶图案的新型功能材料提供了基础。

液晶中电对流图案形成是一种奇特而又有趣的现象，同时也是光衍射研究中的一个重要问题。本文旨在探索负介电各向异性的向列相液晶中图案的形成以及相关的衍射特性。实验观察到4种不同的电对流图案，分别是软方形图案、斜条纹、静脉状图案和不规则图案。探究了不同温度下产生图案所需要的阈值电压。研究了电场对图案的周期性以及相对指向矢倾斜角的影响，并对图案相应的衍射特性进行了分析。实验结果表明，通过调节电场和温度可以改变电对流图案。产生图案所需要的阈值电压随着温度的升高而减小，随着频率的升高而增大。软方形图案的周期随着频率的升高先减小后增大，而斜条纹的周期随频率的升高而减小。当f=25~45Hz时，斜条纹相对于初始指向呈现约44°的偏转。这种可控的电对流图案为实现基于向列相液晶的可调谐光学衍射器件提供了一种可行方案。

We propose a joint look-up-table (LUT)-based nonlinear predistortion and digital resolution enhancement scheme to achieve high-speed and low-cost optical interconnects using low-resolution digital-to-analog converters (DACs). The LUT-based predistortion is employed to mitigate the pattern-dependent effect (PDE) of a semiconductor optical amplifier (SOA), while the digital resolution enhancer (DRE) is utilized to shape the quantization noise, lowering the requirement for the resolution of DAC. We experimentally demonstrate O-band intensity modulation and direct detection (IM/DD) transmission of 124-GBd 4 / 6-level pulse-amplitude modulation ( PAM ) -4 / 6 and 112-GBd PAM-8 signals over a 2-km standard single-mode fiber (SSMF) with 3 / 3.5 / 4-bit DACs. In the case of 40-km SSMF transmission with an SOA-based preamplifier, 124-GBd on-off-keying (OOK)/PAM-3/PAM-4 signals are successfully transmitted with 1.5 / 2 / 3-bit DACs. To the best of our knowledge, we have achieved the highest net data rates of 235.3-Gb / s PAM-4, 289.7-Gb / s PAM-6, and 294.7 Gb / s PAM-8 signals over 2-km SSMF, as well as 117.6-Gb / s OOK, 173.8-Gb / s PAM-3, and -231.8 Gb / s PAM-4 signals over 40-km SSMF, employing low-resolution DACs. The experimental results reveal that the joint LUT-based predistortion and DRE effectively mitigate the PDE and improve the signal-to-quantization noise ratio by shaping the noise. The proposed scheme can provide a powerful solution for low-cost IM/DD optical interconnects beyond 200 Gb / s.

Optical fiber bundles frequently serve as crucial components in flexible miniature endoscopes, transmitting end-to-end images directly for medical and industrial applications. Each core usually acts as a single pixel, and the resolution of the image is limited by the core size and core spacing. We propose a method that exploits the hidden information embedded in the pattern within each core to break the limitation and obtain high-dimensional light field information and more features of the original image including edges, texture, and color. Intra-core patterns are mainly related to the spatial angle of captured light rays and the shape of the core. A convolutional neural network is used to accelerate the extraction of in-core features containing the light field information of the whole scene, achieve the transformation of in-core features to real details, and enhance invisible texture features and image colorization of fiber bundle images.

提出一种基于目标检测算法的柔性浅埋物的声-振智能探测方法，将声波激励、激光散斑干涉测振和目标检测算法有机结合，用以柔性浅埋物的大范围快速探测。在论述YOLO系列目标检测算法原理的基础上，选择并优化柔性浅埋物的智能探测网络模型；然后，搭建声-光融合智能探测系统，构建不同柔性浅埋物的激光散斑干涉条纹图数据集；最后，对数据集进行训练和测试，验证该算法用于干涉条纹图识别的可行性。实验结果表明：在给定实验条件下，柔性浅埋物智能探测网络模型的精确率为98.39%，召回率为84.72%，平均识别精度为99.66%。该声-振智能探测方法可以在给定实验环境下对多种柔性浅埋物的激光散斑干涉条纹图进行智能识别，适用于浅层地下柔性掩埋物的大面积快速探测。

A new electronic speckle pattern interferometry method is proposed to realize in situ deformation measurements. The feature of the method is the combination of a high-speed camera and multiple laser Doppler vibrometers (LDVs) for synchronous measurements. The high-speed camera is used to record and select effective interferograms, while the LDVs are used to measure the rigid body displacement caused by vibrations. A series of effective interferograms with known shifted phase values are obtained to calculate the deformation phase. The experimental results show that the method performs well in measuring static and dynamic deformations with high accuracy in vibrating environments.