啁啾脉冲激光放大的理论与数值模拟分析

Theory and simulation of chirped pulse amplification

为了比较啁啾脉冲在均匀加宽与非均匀加宽介质中传输的特性,采用分步傅里叶方法进行了理论分析和实验验证,得到了增益窄化、增益饱和、自相位调制效应对脉冲在两种不同介质中频域、时域的演化特征曲线。结果表明,在非均匀加宽介质中,增益窄化效应更加明显,而且增益饱和效应得到了很好抑制,两种加宽介质中脉冲的频谱都起到了拓宽作用,非均匀加宽介质中的频谱比较对称,而均匀加宽介质中的频谱出现了畸变。

In order to compare the propagation characteristics of chirped-pulse propagating in homogeneously and inhomogeneously broadening mediums, they were analyzed and simulated by means of split-step Fourier method. Then they were proved in experiments. The effect of gain narrowing, gain saturation and self phase modulation on temporal shape and power spectra in both mediums ~re obtained. It is found that the effect of gain narrowing is more obvious and the effect uf gain saturation is inhibited well in inhomogeneously broadening medium, and power spectra in both mediums are broadened, which is more symmetry in inhomogeneously broadening medium and distortive in homogeneously broadening medium. These results are useful to study the propagation features of chirped-pulse in comprehensive broadening mediums.