Optical imaging techniques provide low-cost, non-radiative images with high spatiotemporal resolution, making them advantageous for long-term dynamic observation of blood perfusion in stroke research and other brain studies compared to non-optical methods. However, high-resolution imaging in optical microscopy fundamentally requires a tight optical focus, and thus a limited depth of field (DOF). Consequently, large-scale, non-stitched, high-resolution images of curved surfaces, like brains, are difficult to acquire without z-axis scanning. To overcome this limitation, we developed a needle-shaped beam optical coherence tomography angiography (NB-OCTA) system, and for the first time, achieved a volumetric resolution of less than 8 μm in a non-stitched volume space of 6.4 mm × 4 mm × 620 μm in vivo. This system captures the distribution of blood vessels at 3.4-times larger depths than normal OCTA equipped with a Gaussian beam (GB-OCTA). We then employed NB-OCTA to perform long-term observation of cortical blood perfusion after stroke in vivo, and quantitatively analyzed the vessel area density (VAD) and the diameters of representative vessels in different regions over 10 days, revealing different spatiotemporal dynamics in the acute, sub-acute and chronic phase of post-ischemic revascularization. Benefiting from our NB-OCTA, we revealed that the recovery process is not only the result of spontaneous reperfusion, but also the formation of new vessels. This study provides visual and mechanistic insights into strokes and helps to deepen our understanding of the spontaneous response of brain after stroke.

对近场分布式光度测量方法及测量机理进行研究，基于自主搭建的近场光源发光特性测量装置采集平面光源不同方向的亮度图像，分析了近场光度参量之间的转换关系及亮度数据处理方法，最终实现了近场分布式平面光源空间光强分布测量。通过构建平面光源发光模型，基于光度学和几何光学原理分析发光平面各个方向的光线分布，完成对光源不同方向的发光状态表征。与远场测量相比，所提近场分布式测量方法结果与远场配光曲线吻合良好，在所采用成像式亮度计亮度相对误差优于6.51%的情况下，所测得的光强相对误差小于8.38%，0°配光曲线匹配指数高达98.33%，验证了所提方法在近场光度测量中的有效性。

光波复振幅中相位信息的恢复是科学与工程领域的重要研究热点之一。相位携带了光传播中的重要信息，对成像与智能感知技术的发展有着重要的意义。相位恢复波前重构技术通过优化算法和设计特定成像装置，从光电探测器采集的强度信息中恢复出难以被直接感知的相位信息，是探测微观和宏观世界的重要技术手段之一，已广泛应用于生物显微、工业检测和天文观测等领域。概述基于干涉和非干涉的波前重构技术及其应用，梳理相位恢复波前重构算法的基本原理和发展历程，对常见相位恢复技术手段如交替投影相位恢复算法、基于调制约束和基于深度学习的相位恢复波前重构技术等进行初步的探讨。针对相位恢复波前重构技术的未来发展提出若干可能的研究方向，包括相位恢复算法的进一步优化、新型系统和器件的开发等。

人脸特征随着年龄变化而变化，会严重影响人脸识别的性能。提出一种基于Transformer的跨年龄人脸识别方法，首先通过改善的T2T-ViT模型提取人脸年龄和身份混合特征，然后通过残差因子分解获取人脸年龄特征和身份特征，再使用线性特征分解的去相关对抗式学习算法对人脸的年龄特征和身份特征去除相关性，从而实现年龄抗干扰性的人脸识别。相比基于卷积神经网络的DAL和MTLFace方法，所提方法在参数量、multiply-add operations（MACs）和计算耗时上均有明显降低，同时在基准数据集AgeDB-30、CACD_VS、CALFW、LFW上取得了相媲美的准确率，证明了所提方法的有效性。