【摘要】 针对高功率激光系统中信噪比低的问题,基于描述超短脉冲传输的非线性薛定谔方程进行数值模拟,研究了高阶群速度色散、光谱调制及自相位调制对脉冲信噪比的影响;新建立了用于分析光栅平整度对脉冲信噪比的影响的物理模型并进行了相应的模拟,分析了光栅的质量要求或补偿精度。研究表明:对于100fs的高斯脉冲,要保证信噪比达到108,应将三阶色散量限制在4.8×105fs3以下,B积分的值应小于0.2,光谱的调制幅度应小于10-4,光栅平整度应优于λ/100。更多还原

【Abstract】 Based on the nonlinear Schrdinger equation,a simulation was carried out to solve the problem of the signal-to-noise ratio being low.The research dealt with the influence of higher-order dispersion,spectral modulation and self-phase-modulation on the signal to noise ratio.Furthermore,a physical model was built to analyze the impact of the flatness of gratings.The results show that for a 100 fs input Gaussian pulse,in order to make the signal-to-noise ratio bigger than 10⁸,the third-orderdispersion should be kept below 4.8×10⁵ fs³,the B-integral below 0.2, the amplitude of the modulation of spectrum below 10^-4 and the flatness of gratings smaller than λ/100.更多还原