低重频高能脉冲多级光纤MOPA系统的优化设计

根据低重频高能脉冲多级光纤主振荡功率放大(MOPA)系统的模型,建立了多级光纤MOPA系统的速率方程和功率传递方程,并提出了一种多级光纤MOPA系统的优化方法.与传统的单个光纤放大器的优化方法相比,该方法把每一级放大器作为系统的一部分,并通过对整个系统结果的分析来优化每一级放大器的参数.对一个两级掺Yb光纤MOPA系统进行了优化模拟计算,在获得基本相同的输出脉冲能量条件下,使用多级光纤MOPA系统优化方法计算得到的第一级光纤优化长度和泵浦功率分别比用传统优化方法得到的结果短3 m和低69.1 W.基于该优化方法,第二级放大器的参数和种子光峰值功率也得到了优化.结果表明:在对多级光纤MOPA系统进行优化时,传统的单光纤放大器优化方法被系统优化方法代替,是用最低成本获得高能量转换效率的保证.

Optimizing design of low-repetition-frequency high-energy pulse amplification in multi-stage fiber MOPA system

According to the model of low-repetition-frequency high-energy pulse amplification in multi-stage fiber master-oscillator-power-amplifier(MOPA)system,the rate and power transfer equations of the MOPA system were constructed,and a new optimal method for the MOPA system was proposed.Compared with the taditional optimal method for single fiber amplifier,the new method considered every amplifter as a part of the whole system and it was optimized by analyzing the whole system.As an example,a two-stage Yb-doped fiber MOPA system was optimized.Under the conditions of almost equal output energy,the optimal fiber length and pump power of the first stage calculated by the proposed method could be 3 m shorter and 69.1 W lower than those calculated by the traditional one,respectively.In addition,based on the new method,parameters of the second stage amplifier and peak power of the seed light source could also be optimized.The result shows that traditional optimal method should be replaced by the proposed method,in order to ensure to achieve a high-energy transfer efficiency at the lowest cost.