The 975 nm multimode diode lasers with high-order surface Bragg diffraction gratings have been simulated and calculated using the 2D finite difference time domain (FDTD) algorithm and the scattering matrix method (SMM). The periods and etch depth of the grating parameters have been optimized. A board area laser diode (BA-LD) with high-order diffraction gratings has been designed and fabricated. At output powers up to 10.5 W, the measured spectral width of full width at half maximum (FWHM) is less than 0.5 nm. The results demonstrate that the designed high-order surface gratings can effectively narrow the spectral width of multimode semiconductor lasers at high output power.

随着电磁环境的日益复杂，电子设备面临的电磁威胁愈加严峻。光电系统作为高灵敏集成化电子设备，强电磁脉冲能量耦合进入系统内部，影响防护能力本就薄弱的光电系统的正常运行。为明晰典型光电系统强电磁耦合过程，通过仿真分析不同强电磁辐照条件下筒型、侧窗型和多窗口型三种典型光电系统的强电磁耦合情况，提取了光电系统强电磁耦合特征及其制约因素，验证了光电系统进行强电磁防护加固的必要性和紧迫性。为解决光电系统强电磁防护能力薄弱的问题，通过仿真分析，验证了透明电磁防护窗口的强电磁加固效能；开展了基于支撑台阶与导电侧壁的电磁缝隙防护加固方法研究，分析了透明防护窗口缝隙耦合泄露的关键安装结构参数，提出了一种非电接触式装配缝隙强电磁防护加固方法。经测试，当缝隙防护结构长度为6 mm时，在0.2～4 GHz频率范围光电系统平均强电磁防护效能提升4.51 dB。研究结果为光电系统强电磁防护能力提升提供了理论指导和具体解决方案。

随着战场环境日益复杂，尤其是高对抗环境下，对现有各类装备均产生了极大威胁。设计了一款C波段雷达接收机保护器，采用充气微波开关管+波导同轴转换的结构设计，创新性地提出将固态限幅器芯片融合在波导同轴转换内部，限幅芯片采用级联的形式，提高了微带限幅器的承受功率。实现接收机保护器耐受功率10 MW以上，响应时间5 ns以内，不仅可用于雷达发射期间接收机防护，还可应对外部电磁干扰、高功率微波攻击。

针对高功率微波波形参数对限幅器温度分布特性的影响，基于双级PIN限幅器的场路协同仿真模型对微波脉冲幅值、频率对温度分布的影响展开了仿真研究。结果表明：微波脉冲幅值、频率的提升会使双级PIN限幅器中PIN二极管的高温区域分布向P区拓展、高温区域分布范围扩大；相对而言，微波脉冲幅值对温度分布的影响更为显著，频率对温度分布的影响相对较小。

A low-numerical-aperture (NA) concept enables large-mode-area fiber with better single-mode operation ability, which is beneficial for transverse mode instability and nonlinear effects suppression. In this contribution, we reported a high-power fiber amplifier based on a piece of self-developed large-mode-area low-NA fiber with a core NA of 0.049 and a core/inner cladding diameter of 25/400 µm. The influence of the pump wavelength and fiber length on the power scaling potential of the fiber amplifier is systematically investigated. As a result, an output of 4.80 kW and a beam quality factor of ∼1.33 were finally obtained, which is the highest output power ever reported in a fiber amplifier exploiting the low-NA fiber. The results reveal that low-NA fibers have superiority in power scaling and beam quality maintenance at high power levels.

大功率白光LED封装主要分为玻璃荧光片封装和荧光粉胶封装。本文提出一种用荧光胶封装大功率白光LED的方法，优化白光LED的发光面的均匀性，并分析了荧光胶封装和用荧光片封装的大功率白光LED的光热性能。实验结果表明，在1 400 mA电流驱动下，荧光胶封装白光LED的光通量为576.07 lm，比荧光片封装白光LED的光通量高15.5%，光转换效率为35.8%。在温度从25 ℃提升到125 ℃的过程中，荧光胶封装器件的亮度衰减了20%，色温从5 882.11 K提高到6 024.22 K。荧光胶封装的白光LED在常温下的热阻为1.7 K/W，与玻璃荧光片封装的热阻接近。在840 h高温高湿老化和1 600 h高温老化实验中，荧光胶封装的相对光衰均能稳定在97%。