多程放大中激光脉冲交叠放大的物理建模与计算方法

摘要

建立了多程放大中激光脉冲在增益介质中交叠放大的物理模型，并提出相应的计算方法。物理模型中考虑了脉冲前后沿对增益介质中反转粒子数的共同消耗。研究认为模型在延时系下的数据递推方式无法求解交叠放大问题。通过建立新的时空坐标系，解决了交叠放大过程的数值求解问题。基于此物理模型和计算方法，模拟计算了双程放大时脉冲时间波形与腔镜位置的关系。%Physical model and caculation method are established to describe the laser pulse superpositon in multi-pass amplification process. In this model, the inversion pupulation density is consumed by the pulse leading edge and tailing edge simultaneously. It is demon-strated that this model can not solve the problem of laser superposition amplification in the time-delay coordination. The superposition amplification is solved by building a new time-space coorination. Base on the physical model and caculation method, computer simu-lation is performed and the pulse shape distortion is discussed at different cavity mirror positions in two-pass amplification process.