Holographic display stands as a prominent approach for achieving lifelike three-dimensional (3D) reproductions with continuous depth sensation. However, the generation of a computer-generated hologram (CGH) always relies on the repetitive computation of diffraction propagation from point-cloud or multiple depth-sliced planar images, which inevitably leads to an increase in computational complexity, making real-time CGH generation impractical. Here, we report a new CGH generation algorithm capable of rapidly synthesizing a 3D hologram in only one-step backward propagation calculation in a novel split Lohmann lens-based diffraction model. By introducing an extra predesigned virtual digital phase modulation of multifocal split Lohmann lens in such a diffraction model, the generated CGH appears to reconstruct 3D scenes with accurate accommodation abilities across the display contents. Compared with the conventional layer-based method, the computation speed of the proposed method is independent of the quantized layer numbers, and therefore can achieve real-time computation speed with a very dense of depth sampling. Both simulation and experimental results validate the proposed method.

Friction plays a critical role in dexterous robotic manipulation. However, realizing friction sensing remains a challenge due to the difficulty in designing sensing structures to decouple multi-axial forces. Inspired by the topological mechanics of knots, we construct optical fiber knot (OFN) sensors for slip detection and friction measurement. By introducing localized self-contacts along the fiber, the knot structure enables anisotropic responses to normal and frictional forces. By employing OFNs and a change point detection algorithm, we demonstrate adaptive robotic grasping of slipping cups. We further develop a robotic finger that can measure tri-axial forces via a centrosymmetric architecture composed of five OFNs. Such a tactile finger allows a robotic hand to manipulate human tools dexterously. This work could provide a straightforward and cost-effective strategy for promoting adaptive grasping, dexterous manipulation, and human-robot interaction with tactile sensing.

为实现高功率的蓝光半导体激光输出，对蓝光巴条的封装技术进行了研究。利用金锡硬焊料封装了高功率氮化镓（GaN）蓝光半导体激光巴条，应用铜钨过渡热沉作为缓冲层抑制了铜热沉和GaN激光芯片之间封装残余应力，采用高精度贴片机将芯片共晶键合在铜钨过渡热沉上。贴片质量的好坏直接影响了器件的输出特性，所以重点分析了贴片机的焊接温度焊接压力、焊接时间对器件的影响。实验结果表明：当贴片机的焊接温度为320 ℃、焊接压力为0.5 N、焊接时间为40 s时，焊料层界面空洞最少，热阻最低为0.565 ℃/W，阈值电流最低为4.9 A，在注入电流30 A时，输出光功率最高为32.21 W，最高光电转换效率达到了23.3%。因此，在优化焊接温度、焊接压力、焊接时间后，利用金锡硬焊料将蓝光半导体激光芯片共晶键合在铜钨过渡热沉的技术方案是实现蓝光半导体激光巴条高功率工作的有效途径。

在压水堆正常运行期间，氚贡献了压水堆液相流出物总活度的95%以上，是反应堆设计和运行中的关键放射性核素之一。通过对美国在运的8台堆芯设计非常相似的机组2000至2019年期间氚排放数据进行较为深度的数据清洗和分析研究，得出采用不锈钢包壳的Sb-Be次级中子源的氚释放是压水堆机组氚源项的重要来源之一，统计机组中次级中子源产氚贡献平均为7.5 TBq·a⁻¹，结合理论计算，符合当前包壳材料发展和运行管理水平下的渗透比例10%～20%。取消次级中子源约可以降低20%的因氚排放造成的公众剂量，还可以降低氚源项对厂址规划机组数量的制约。此外，研究还发现，氚排放量的显著波动受到液态集中排放的显著影响，特别是在美国压水堆大修之前或期间，这将有助于优化未来机组放射性排放管理。

Four-channel off-axis holography is proposed to simultaneously understand the polarization states and the mode coefficients of linearly polarized (LP) modes in few-mode fiber. Far-field off-axis holograms in the four polarization directions of the fiber laser were acquired at the same moment through a four-channel holographic device. The weights, the relative phase differences, and the polarization parameters of the vector fiber laser mode can be solved simultaneously. The simulated and experimental mode analysis of the laser output by 1060-XP fiber with 6 LP modes at 632.8 nm is conducted, which shows that the similarity of the total intensity distribution of the laser before and after mode analysis is above 0.97. The mode polarization states, the mode weights, and the relative phase differences of the few-mode laser can be determined simultaneously in a single shot by four-channel off-axis holography.

氮化镓作为第三代照明器件材料相较于第一代硅与第二代砷化镓在性能上有了很大提高，基于氮化镓的Micro-LED器件也愈发被人们所关注。然而由于在传统c面上生长的LED其自身所固有的一些缺陷往往在实际应用中发射效率不高，如存在量子限制斯塔克效应、绿色间隙、载流子传输等问题。基于非极性或半极性的LED没有极化电场，具有较强的内量子效率，电子和空穴复合机率大等优点，对非极性和半极性Micro-LED器件的研究与应用引起了人们很大的兴趣。本文对非极性和半极性Micro-LED器件研究现状进行综述。首先从量子限制斯托克效应、绿色间隙、载流子传输、效率下降4个方面介绍了非极性和半极性氮化镓基材料的优势。接着针对缺陷位错、增加光提取效率与在不同电流密度下实现全彩显示等问题，介绍了芯片成形、图案刻蚀与阵列这3种技术，最后对Micro-LED作为下一代显示引领者进行了展望。希望对Micro-LED今后的研究有所帮助。