高能超短脉冲激光的相干合成研究

Ultrahigh intensity is one of the goals to pursue in the development of laser technology. However, the output capability of single beam is limited by the effects such as strong nonlinear effects and damage threshold of optical components. Compared with the single-beam amplification, coherent combination of the muti-beam is an attractive approach for ultrahigh output power density. In high-energy ultrashort pulse laser facilities, the coherent beam combination is affected by many factors(for example: environmental vibration, shock-produced deformation and thermal strain). So, specific techniques are needed to realize the inphase of ultrashort pulses for the coherent combination. This project will study the coherent combination of ultrashort pulses. This research can provide the theoretical basis and the experimental guide for the coherent combination of ultrashort pulses in solid-state laser facilities.

超高强度是激光技术发展追求的目标之一。受限于强激光的非线性效应及光学元件损伤等因素，单路激光器的输出能力是有限的，而将多束激光进行相干合成可以获得极高的输出功率密度。在高能超短脉冲激光装置中，光束的相干合成会受到多种因素的影响（比如：环境振动、泵浦产生的冲击形变和热畸变等），要实现多束超短脉冲激光的相干合成，必须采取一定技术手段使激光束实现共相输出。本课题拟针对超短脉冲激光的相干合成展开研究，为固体激光装置中进行多束超短脉冲激光的相干合成提供理论基础和实验指导。

超短超强脉冲激光能够产生极端的物态条件，为强场物理、等离子体物理、惯性约束聚变、实验室天体物理等很多前沿科学领域提供强有力的手段。由于强激光的非线性效应、光学元件损伤等因素的限制，单路超短脉冲激光的输出能力已经不能满足不断增长的物理实验的需求。为获得更高的聚焦功率密度，本项目针对超短脉冲激光的相干合成进行了分析研究，提出了一种基于时域互相关和远场干涉信息的超短脉冲激光束间误差的快速探测补偿技术，实现了两束小口径毫焦级30飞秒超短脉冲激光相干合成的原理性验证，最大合成效率99%，平均合成效率80.3%。本项目的研究结果为后续工作的开展积累了基础和经验。