Free-space optical information transfer through diffusive media is critical in many applications, such as biomedical devices and optical communication, but remains challenging due to random, unknown perturbations in the optical path. We demonstrate an optical diffractive decoder with electronic encoding to accurately transfer the optical information of interest, corresponding to, e.g., any arbitrary input object or message, through unknown random phase diffusers along the optical path. This hybrid electronic-optical model, trained using supervised learning, comprises a convolutional neural network-based electronic encoder and successive passive diffractive layers that are jointly optimized. After their joint training using deep learning, our hybrid model can transfer optical information through unknown phase diffusers, demonstrating generalization to new random diffusers never seen before. The resulting electronic-encoder and optical-decoder model was experimentally validated using a 3D-printed diffractive network that axially spans <70λ, where λ = 0.75 mm is the illumination wavelength in the terahertz spectrum, carrying the desired optical information through random unknown diffusers. The presented framework can be physically scaled to operate at different parts of the electromagnetic spectrum, without retraining its components, and would offer low-power and compact solutions for optical information transfer in free space through unknown random diffusive media.

应用于强流重离子加速器装置增强环（HIAF-BRing）的快循环全储能脉冲电源需要在极宽的输出电压范围内保持极高的控制精度，为此电源采用了高压功率单元和低压功率单元串联的拓扑方式，在低压段采用低压功率单元，电压升高之后切换到高压功率单元，通过高低压切换控制来实现电流全阶段的高精度输出。但是在样机实测中发现存在切换点的振荡问题，导致切换点处的输出电流绝对误差无法满足指标要求。本文提出了一种切换点平滑控制算法来平滑处理切换点占空比，给出了仿真结果，并且在HIAF-BRing快循环全储能脉冲电源样机上面实际验证了高低压切换控制方法及其切换点平滑控制算法的有效性。实验结果表明：100 A注入平台的输出电流绝对误差由±500 mA降至±50 mA，100 A注入平台的切换点处输出电流绝对误差由±1.16 A降至±120 mA，100 A注入平台输出精度较低的问题得以解决。

低噪声激光器是空间激光干涉仪引力波探测器的核心组件之一，激光器的输出功率、强度噪声、频率噪声等性能直接影响空间引力波探测器的灵敏度。空间引力波探测器对激光器的结构设计、噪声水平等提出了严格的要求。本文介绍了空间引力波探测器的目标和对激光器的要求，分析了激光器噪声性能对探测器灵敏度的影响，梳理了国内外典型探测任务中低噪声激光器研究进展，比较了不同激光器的噪声性能。最后，阐述了强度噪声抑制和频率噪声抑制的原理和进展，并对国内空间引力波探测用的低噪声激光器的研究进行了展望。

高Al组分的AlGaN材料的光谱响应范围在日盲紫外波段，但其表面较高的缺陷密度限制了其在日盲紫外探测领域的应用。为此，研究了表面修饰对AlGaN基日盲紫外光电探测器件的性能影响。采用化学自组装方法，将十八硫醇有机分子化学吸附在高Al组分的Al_0.6Ga_0.4N表面，制备出表面修饰的AlGaN基金属-半导体-金属型日盲紫外光电探测器件。与未经修饰的光电探测器对比验证了这种修饰过程能有效减少AlGaN材料的表面状态引起的不利影响，降低器件的漏电流，并显著提高器件响应度，从而实现具有高响应度的AlGaN基金属-半导体-金属型日盲紫外光电探测器制备。

强流重离子加速器装置（HIAF）的增强器（BRing）二极铁电源样机采用多模块串并联的全储能快循环脉冲电源实现方案，电源功率达到MW级。由于电源规模庞大和功率巨大，为了在运行中迅速保护电源设备，设计并实现了一套双冗余的基于可编程逻辑控制器（PLC）、模块故障联锁板和现场可编程门阵列（FPGA）的模块故障联锁保护系统，利用硬件和软件同时对电源功率单元模块实施故障检测、故障传递和故障保护。设计完成后分别从电源联锁环路的响应时间、核心控制板故障引发电源环路联锁的总时间和设备故障响应等三个方面进行测试，测试结果表明，在电源发生故障时，模块故障联锁保护系统满足电源样机对实时性和可靠性的要求，达到设计目标。

We have fabricated the AlGaN solar-blind ultraviolet metal–semiconductor–metal (MSM) photodetectors (PDs) with an Al composition of 0.55. The surface roughness and dislocations of the high-Al-content Al0.55Ga0.45N epitaxial layer are analyzed by atomic force microscopy and transmission electron microscopy, respectively. The device exhibits high spectral responsivity and external quantum efficiency due to the photoconductive gain effect. The current reveals a strong dependence on high temperatures in the range of 4–10 V. Moreover, the Poole–Frenkel emission model and changing space charge regions are employed to explain the carrier transport and photoconductive gain mechanisms for the AlGaN PD, respectively.