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.

光栅干涉仪位移测量系统作为测量领域中最精密的测量仪器之一，由于在测量过程中光栅的姿态位置无法保证完美装配，使得光栅的光栅矢量方向与运动矢量方向之间出现偏差，导致位移测量结果出现周期性非线性误差。文中针对在光栅干涉仪位移测量过程中出现的光栅与位移台以及读数头之间的姿态位置误差进行分析，通过分别建立位移坐标系及光栅坐标系，参考惯性导航领域中飞行器姿态表示方法，利用一维光栅的横滚、俯仰和偏航角共同描述一维光栅相对于位移台的装配状态。通过基于矢量衍射理论分析光栅干涉仪位移测量时三个维度的角度偏差量，对可能产生的位移测量误差进行了分析说明。基于广义一维光栅方程，探究出了一个更为普遍的结论，为后续装置的改进提供理论依据，以提高系统的测量精度。

The design of nonlinear photonic Vogel’s spiral based on quasi-crystal theory was demonstrated. Two main parameters of Vogel’s spiral were arranged to obtain multi-reciprocal circles. Typical structure was fabricated by the near-infrared femtosecond laser poling technique, forming a nonlinear photonic structure, and multiple ring-like nonlinear Raman–Nath second-harmonic generation processes were realized and analyzed in detail. The structure for the cascaded third-harmonic generation process was predicted. The results could help deepen the understanding of Vogel’s spiral and quasi-crystal and pave the way for the combination of quasi-crystal theory with more aperiodic structures.

On-chip diffractive optical neural networks (DONNs) bring the advantages of parallel processing and low energy consumption. However, an accurate representation of the optical field’s evolution in the structure cannot be provided using the previous diffraction-based analysis method. Moreover, the loss caused by the open boundaries poses challenges to applications. A multimode DONN architecture based on a more precise eigenmode analysis method is proposed. We have constructed a universal library of input, output, and metaline structures utilizing this method, and realized a multimode DONN composed of the structures from the library. On the designed multimode DONNs with only one layer of the metaline, the classification task of an Iris plants dataset is verified with an accuracy of 90% on the blind test dataset, and the performance of the one-bit binary adder task is also validated. Compared to the previous architectures, the multimode DONN exhibits a more compact design and higher energy efficiency.

在氟化物熔盐相直接将UF₆中转化为UF₄是熔盐堆燃料盐的合成及重构的候选工艺之一。其中，UF₃是该工艺过程的重要中间产物，其含量是开展工艺研究的关键参数之一。本文采用X射线衍射（X-ray Diffraction，XRD）内标法测量氟化物体系中的UF₃含量，分析了不同组分的固态熔盐样品，建立了UF₃含量的测量分析方法。首先以刚玉（α-Al₂O₃）为内标，获得了UF₃在1.00~10.00 wt%含量范围时，LiF-BeF₂-UF₃熔盐的XRD峰高度内标曲线（R=0.986）和峰面积内标曲线（R=0.995）。然后应用这两条内标曲线测量已知含量的LiUF₅和UF₃固体混合样品，结果表明峰面积内标曲线具有更好的准确度，测量相对误差不大于8.7%。最后分别对快速冷却的LiF-BeF₂-UF₃固态熔盐样品和自然冷却的LiF-BeF₂-UF₃-LiUF₅固态熔盐样品进行测量，测量结果的相对误差不大于5.4%。以上结果表明：本文建立的XRD内标法可以用于混合氟盐样品的UF₃分析，并具有较好的测量精度和重复性。

研究了富勒烯对六官能团脂肪族聚氨酯丙烯酸酯/环氧树脂(RJ423/ EPIKOTE 828)体系光致聚合物的全息性能的影响，分析了富勒烯(C₆₀)材料以及曝光光强对光致聚合物衍射效率的影响。通过吸收光谱结合X射线衍射图谱分析，掺杂的富勒烯既没有和聚合物中的其他成分发生化学反应，也不影响材料本身的结构和结晶性能。实验结果表明，富勒烯掺杂提高了单体聚合反应的速率，并且参与活性单体分子之间的扩散。在光强20 mW/cm²、时间40～50 s、厚度200 μm时，光致聚合物的衍射效率提升到86%，感光灵敏度达到1.32 cm²/J，收缩率降低了约80%。由于C₆₀促进聚合，抑制体积收缩，从而增强全息存储的稳定性，经过全息图像存储实验对比，证明该光致聚合物掺杂富勒烯之后具有优秀的全息存储性能，同时也表明富勒烯掺杂的光致聚合物在全息储存领域具有较大的应用前景。