激光驱动动态压缩实验是极端高压高密度研究的主要途径，在多个学科领域具有重要意义，包括地球行星科学，材料科学以及惯性约束聚变，有助于认识极端条件下的材料特性并拓展其在各学科的应用。近年来激光驱动压缩技术在激光装置、激光等离子体、制靶和诊断技术的同步提升下取得了突破性的进展，与其他极端条件实验平台相比，其斜波压缩、复杂路径、衰减冲击等新型加载路径得到快速发展，微介观诊断技术和宏观诊断技术相结合，具有明确的超高压、高温、高应变率以及高同步精度等技术特色。从激光驱动材料压缩的热力学路径、激光驱动的机制与特色、激光驱动实验技术、材料极端压缩物理进展等方面介绍激光驱动实验和理论方面的进展。

基于一维弹塑性磁流体力学程序（SSS-MHD），研究了反场构型（FRC）等离子体靶在磁驱动固体套筒压缩过程中强磁场对α粒子能量约束效应，分析了α粒子的非局域和局域自加热对FRC等离子靶压缩峰值温度的影响，以及α粒子能量在整个压缩过程中端部损失效应。等离子体部分采用多温单流体的模型，能量的计算中引入了DT离子、电子及α粒子多成分温度的能量方程，同时考虑了等离子体压缩过程热平衡下的核反应和非局域自加热问题。研究结果表明，磁化靶聚变等离子体在压缩过程中具有较好的稳定性，能够保持刚性转子的靶结构，压缩过程形成的强磁场能够将α粒子的能量约束在O点附近的区域，有利于等离子体靶的点火及燃烧；α粒子对等离子体的自加热效应主要集中在等离子体电流中心区，而非等离子体中心轴处；α粒子对DT等离子体局域和非局域自加热过程存在差异，局域自加热过程的功率大于非局域自加热过程的功率，FRC等离子靶压缩峰值状态温度相差0.5倍。在反场构型的刮离层区，α粒子的能量端部损失在FRC等离子体靶的压缩和膨胀过程中逐渐增大。

The miniaturization of polarization beam splitters (PBSs) is vital for ultradense chip-scale photonic integrated circuits. However, the small PBSs based on complex hybrid plasmonic structures exhibit large fabrication difficulties or high insertion losses. Here, by designing a bending multimode plasmonic waveguide, an ultrabroadband on-chip plasmonic PBS with low insertion losses is numerically and experimentally realized. The multimode plasmonic waveguide, consisting of a metal strip with a V-shaped groove on the metal surface, supports the symmetric and antisymmetric surface plasmon polariton (SPP) waveguide modes in nature. Due to the different field confinements of the two SPP waveguide modes, which result in different bending losses, the two incident SPP waveguide modes of orthogonal polarization states are efficiently split in the bending multimode plasmonic waveguide. The numerical simulations show that the operation bandwidth of the proposed PBS is as large as 430 nm because there is no resonance or interference effect in the splitting process. Compared with the complex hybrid plasmonic structure, the simple bending multimode plasmonic waveguide is much easier to fabricate. In the experiment, a broadband (Δλ≈120 nm) and low-insertion-loss (<3 dB with a minimum insertion loss of 0.7 dB) PBS is demonstrated by using the strongly confined waveguide modes as the incident sources in the bending multimode plasmonic waveguide.

The formation of long plasma channels and laser-induced high-voltage discharges are demonstrated by focusing infrared picosecond laser pulses in air. Based on measurements of the channel conductivity, the maximum electron density in excess of 1014 cm 3 is estimated. The plasma channels are good conductors, through which long-air-gap high-voltage discharges are triggered. The breakdown voltages show large drops but the discharging paths are not well guided: in this, the plasma spots distributed along the channel might play an important role.