研究了大口径级联空间滤波器中色差造成的离焦色散与传输时间延迟对超短脉冲波形与时间信噪比的影响。针对神光-5 PW高功率超短脉冲系统,通过数值模拟,定量分析了光束口径、色差等因素与近远场脉冲波形畸变和时间信噪比退化的关系。从脉冲波形和时间信噪比的角度,给出了大口径空间滤波器消色差后残余色差的容忍范围,为高功率超短脉冲系统中空间滤波器的设计与优化提供了理论依据。

The influences of defocus dispersion and propagation time delay, which are caused by the chromatic aberration in cascade large-diameter spatial filters, on the ultra-short pulse shape and the temporal contrast are investigated. The relationship among beam diameter, chromatic aberration, pulse shape distortion and temporal contrast degradation in both near and far fields is quantitatively analyzed by the numerical simulation. From the perspective of pulse shape and temporal contrast, the tolerance range of residual chromatic aberration from large-diameter spatial filters after achromatism is given, which provides a theoretical foundation for the design and optimization of spatial filters in a high power ultra-short pulsed laser system.