【摘要】 基于啁啾脉冲激光放大原理 ,从Maxwell波动方程出发 ,建立了描述脉冲在啁啾放大系统中传播的非线性薛定谔方程 ,系统研究了啁啾脉冲在放大过程中增益窄化效应对频域内的光谱和时域内的脉宽造成的影响 .结果表明 ,在放大过程中 ,脉冲频谱及其时间结构均将随小信号增益的增大和放大介质增益带宽的减小而逐步变窄 ,其相应压缩后的脉冲时间宽度将增大 .在此基础上 ,提出并分析了利用再生腔内插入一定线型的损耗元件来减弱或消除这一效应 ,获得进一步改善放大器工作特性的效果更多还原

【Abstract】 Based on the principle of chirped pulse amplification technique and the well known Maxwell Wave Equation, a nonlinear Schrodinger equation is established which can describe the whole traveling process of chirped laser pulses in amplifiers. The gain narrowing effect causing distorted amplified spectra, time structure and recompressed time duration, is numerically analyzed in detail. These results show that with the increase of small signal gain and the decrease of gain bandwidth of an amplifier, both the spectral bandwidth and the temporal duration of an amplified pulse will become narrower while its recompressed autocorrelation trace will become wider. In order to reduce or eliminate this negative effect, we proposed a new method by introducing special spectrum filters intracavity. As a result, the improved laser amplification quality is clearly demonstrated.更多还原