多个超短脉冲相干叠加构成窄带平顶长脉冲的研究

利用超短脉冲放大过程中的光谱增益窄化效应以及标准具的滤波作用,提出了基于再生放大器的多脉冲相干叠加方案，并对该方案在多脉冲叠加阶段的工作原理进行了分析；在小信号增益区内，对多个超短脉冲相干叠加进行了理论分析和数值计算，数值模拟的结果表明，影响形成窄带平顶长脉冲的基本关系为子脉冲宽度、再生放大器中的损耗及其与振荡器的长度失配量对构成脉冲时间波形影响很大，而对其频谱影响很小；叠加脉冲个数、标准具的通带宽度对构成脉冲波形和光谱均有影响. 关键词： 超短脉冲 多脉冲叠加器 窄带平顶长脉冲 数值计算

Research on the formation of narrow bandwidth long flat-top pulse via coherent addition of ultra-short pulses

Making use of the spectrum gain narrowing effect during the ultra-short pulse amplification in the gain media and the filter effect of the etalon, and adopting the principles of the regenerative amplifier, the multi-pulse coherent addition scheme is proposed and analyzed. In the small signal gain region of the ultra-short pulse amplification in the regenerative amplifier, theoretical analysis and numerical simulation have been made on the multi-pulse coherent addition stage. The simulation suggests that the width of the sub-pulse, the loss in the regenerative amplifier and the mismatch between the oscillator and the regenerative amplifier are the key factors affecting the temporal shape of the composite pulse, although they have little influence on its spectrum. Both the numbers of the constituent sub-pulses and the bandwidth of the etalon have influence on the shape and spectrum of the pulse.