宽带光学参变啁啾脉冲放大系统的色散控制

Dispersion Control in Broadband Optical Parametric Chirped-Pulse Amplification Laser System

在设计宽带光学参变啁啾脉冲放大系统时,对色散源进行了理论分析和讨论。对光学参变啁啾脉冲放大系统的色散量以及各个过程中的高阶色散对脉冲时域和频域特性的影响进行了计算。结果表明展宽器引入了非常大的色散,放大器中信号光相位变化产生的色散较大,参量晶体本身引入的色散相对较小可以忽略不计。输出脉冲宽度主要受二阶色散影响,而三阶和四阶色散主要影响脉冲的波形和信噪比,对频域影响很小。

The dispersion of a broadband optical parametric chirped pulses amplification （OPCPA） laser system is investigated. Using the numerical method, the theoretical model of dispersion and the effects of high-order dispersion on the charateristics in temporal and frequency domain of signal pulses are presented in broadband OPCPA laser system. The results demonstrate that dispersion induced by the pulse stretcher and phase change of signal pulses in the amplifier is relatively great, but the dispersion of parametric crystal can be ignored. The pulse duration is mainly controlled by the second-order dispersion, and the pulse signal-noise-ratio and waveform affected by third-order dispersion and fourth-order dispersion. However, the change of pulse frequency from dispersion is negligible.