脉冲时域相干合成技术主要通过对功率放大后的高重频脉冲序列进行时序合成，从而降低激光的重复频率，有效地提升输出脉冲的峰值功率与能量，避免放大过程中高峰值功率引起的非线性效应。该技术与空域相干合成相结合，能够突破单纤激光的性能极限，实现高能量、高平均功率和高峰值功率的超短脉冲激光输出，具有广阔的应用前景。介绍了超短脉冲光纤激光时域相干合成的基本原理和关键技术，综述了时域相干合成系统的发展历程及其关键技术的研究现状，重点介绍了近年来脉冲分割放大与脉冲相干堆积技术的研究进展，并对时域相干合成的不同技术路线进行了分析与比较，最后对其未来的发展方向进行了梳理，为相关领域的研究提供参考。

基于单光子探测的距离选通成像系统中，需发射短脉冲激光并进行发射器和接收器之间的同步控制，使探测器工作在光子计数模式并在时间上进行积分，以完成成像操作。为了获得满足系统要求的短脉冲激光，同时减小系统体积、降低系统成本，本文提出将基于射频双极晶体管和基于阶跃恢复二极管SRD(结合短路传输线)两种产生窄脉冲电路应用于单光子距离选通成像系统。介绍了二者的原理与设计方法，进行了仿真验证、实物制作及测试，对脉冲发生器的特点、影响脉宽幅值的因素进行了分析。实物测试结果表明，基于晶体管方式可以产生上升时间为903.5 ps、下降时间为946.1 ps、脉冲宽度为824 ps、幅度为2.46 V的窄脉冲。基于SRD方式可以产生上升时间为456.8 ps、下降时间为458.3 ps、脉冲宽度为1.5 ns、幅度为2.38 V的窄脉冲，二者重复频率皆可达到50 MHz。利用这两种设计方法的任何一种配合外部电流驱动激光二极管都能够获得性能优良的短脉冲激光输出。

As optical parametric chirped pulse amplification has been widely adopted for the generation of extreme intensity laser sources, nonlinear crystals of large aperture are demanded for high-energy amplifiers. Yttrium calcium oxyborate (YCa₄O(BO₃)₃, YCOB) is capable of being grown with apertures exceeding 100 mm, which makes it possible for application in systems of petawatt scale. In this paper, we experimentally demonstrated for the first time to our knowledge, an ultra-broadband non-collinear optical parametric amplifier with YCOB for petawatt-scale compressed pulse generation at 800 nm. Based on the SG-II 5 PW facility, amplified signal energy of approximately 40 J was achieved and pump-to-signal conversion efficiency was up to 42.3%. A gain bandwidth of 87 nm was realized and supported a compressed pulse duration of 22.3 fs. The near-field and wavefront aberration represented excellent characteristics, which were comparable with those achieved in lithium triborate-based amplifiers. These results verified the great potential for YCOB utilization in the future.

Using two infrared pulsed lasers systems, a picosecond solid-state Nd:YAG laser with tuneable repetition rate (400 kHz–1 MHz) working in the burst mode of a multi-pulse train and a femtosecond Ti:sapphire laser amplifier with tuneable pulse duration in the range of tens of femtoseconds up to tens of picoseconds, working in single-shot mode (TEWALASS facility from CETAL-NILPRP), we have investigated the optimal laser parameters for kinetic energy transfer to a titanium target for laser-thrust applications. In the single-pulse regime, we controlled the power density by changing both the duration and pulse energy. In the multi-pulse regime, the train’s number of pulses (burst length) and the pulse energy variation were investigated. Heat propagation and photon reflection-based models were used to simulate the obtained experimental results. In the single-pulse regime, optimal kinetic energy transfer was obtained for power densities of about 500 times the ablation threshold corresponding to the specific laser pulse duration. In multi-pulse regimes, the optimal number of pulses per train increases with the train frequency and decreases with the pulse power density. An ideal energy transfer efficiency resulting from our experiments and simulations is close to about 0.0015%.