The use of broadband laser technology is a novel approach for inhibiting processes related to laser plasma interactions (LPIs). In this study, several preliminary experiments into broadband-laser-driven LPIs are carried out using a newly established hundreds-of-joules broadband second-harmonic-generation laser facility. Through direct comparison with LPI results for a traditional narrowband laser, the actual LPI-suppression effect of the broadband laser is shown. The broadband laser had a clear suppressive effect on both back-stimulated Raman scattering and back-stimulated Brillouin scattering at laser intensities below 1 × 10¹⁵ W cm^-2. An abnormal hot-electron phenomenon is also investigated, using targets of different thicknesses.

海洋立体结构信息是未来实现海洋透明与海洋强国的基础，针对海洋剖面探测能力不足的问题，以及星载海洋剖面多要素同源同域一体化探测空白，开展星载海洋剖面多要素探测技术与系统方案研究，提出新型激光主被动复合、能谱复用探测技术体制，面向未来星载应用，完成星载海洋剖面多要素探测载荷系统设计。其中，激光器谱段设计为486、532 nm多波长一体化最佳配比输出，光电接收探测系统选用1 m×5 m超大口径可折叠光栅主镜，经过仿真分析，探测系统可实现大洋水深100 m深度、温度、盐度以及后向散射系数等多要素同源探测能力，同等体积包络条件下，能量收集能力提升5倍。

基于LED光源的低强度光治疗（LLLT）是一项快速发展的非侵入式光治疗技术。相比于激光，LED光疗能轻易产生较大面积的治疗光斑，并且获得与激光几乎一致的治疗效果。在LED光疗仪设计及光疗方案制定时，考虑到边缘光线与皮肤间角度过大会影响光的穿透效果，因此需要一个皮肤模型分析大面积光斑时的光穿透情况。首先，本论文根据皮肤组织的光学特性建立了一个通用的皮肤模型样本。然后，利用蒙特卡洛模拟方法对LED光源发出的光进行追迹，并分析了不同波长、不同发散角的光，在该样本中的光分布和能量吸收情况。最后，根据人体肩部、前臂背侧、臀部三个部位皮肤的参数，与样本模型进行对照，验证模型的可靠性。模拟的最终结果给出了大尺寸LED光斑在皮肤中的传输情况，并且在不同部位皮肤的模拟实验中，均得到需要将光斑发散半角控制在30°以内的结论，为LED光治疗领域提供了重要参考。

Metasurfaces composed of spatially arranged ultrathin subwavelength elements are promising photonic devices for manipulating optical wavefronts, with potential applications in holography, metalens, and multiplexing communications. Finding microstructures that meet light modulation requirements is always a challenge in designing metasurfaces, where parameter sweep, gradient-based inverse design, and topology optimization are the most commonly used design methods in which the massive electromagnetic iterations require the design computational cost and are sometimes prohibitive. Herein, we propose a fast inverse design method that combines a physics-based neural network surrogate model (NNSM) with an optimization algorithm. The NNSM, which can generate an accurate electromagnetic response from the geometric topologies of the meta-atoms, is constructed for electromagnetic iterations, and the optimization algorithm is used to search for the on-demand meta-atoms from the phase library established by the NNSM to realize an inverse design. This method addresses two important problems in metasurface design: fast and accurate electromagnetic wave phase prediction and inverse design through a single phase-shift value. As a proof-of-concept, we designed an orbital angular momentum (de)multiplexer based on a phase-type metasurface, and 200 Gbit/s quadrature-phase shift-keying signals were successfully transmitted with a bit error rate approaching 1.67×10-6. Because the design is mainly based on an optimization algorithm, it can address the “one-to-many” inverse problem in other micro/nano devices such as integrated photonic circuits, waveguides, and nano-antennas.

Optical logical operations demonstrate the key role of optical digital computing, which can perform general-purpose calculations and possess fast processing speed, low crosstalk, and high throughput. The logic states usually refer to linear momentums that are distinguished by intensity distributions, which blur the discrimination boundary and limit its sustainable applications. Here, we introduce orbital angular momentum (OAM) mode logical operations performed by optical diffractive neural networks (ODNNs). Using the OAM mode as a logic state not only can improve the parallel processing ability but also enhance the logic distinction and robustness of logical gates owing to the mode infinity and orthogonality. ODNN combining scalar diffraction theory and deep learning technology is designed to independently manipulate the mode and spatial position of multiple OAM modes, which allows for complex multilight modulation functions to respond to logic inputs. We show that few-layer ODNNs successfully implement the logical operations of AND, OR, NOT, NAND, and NOR in simulations. The logic units of XNOR and XOR are obtained by cascading the basic logical gates of AND, OR, and NOT, which can further constitute logical half-adder gates. Our demonstrations may provide a new avenue for optical logical operations and are expected to promote the practical application of optical digital computing.