啁啾脉冲堆积的宽带整形脉冲三倍频方案分析

Third Harmonic Generation of Broadband Shaping Pulse by Chirped Pulse Stacking Method

针对啁啾脉冲堆积方法获得的宽带整形激光脉冲,采用KDP晶体I/II类角度失谐的三倍频方案,定量分析了影响其三倍频转换效率的主要因素,并对三倍频前后的时间波形及频谱分布进行了比较分析。在此基础上,与时间相位调制的宽带整形脉冲三倍频的相应结果进行了比较。研究结果表明,对于啁啾脉冲堆积方法获得的宽带整形激光脉冲,在实现较高的三倍频转换效率的同时,其时间波形和频谱分布基本保持不变。对于具有相同带宽和波形的时间位相调制整形脉冲,其三倍频转换效率明显低于啁啾脉冲堆积宽带整形脉冲。

For the broadband shaping laser pulse obtained by chirped pulse stacking （CPS）method, the main factors affecting on the third harmonic conversion efficiency of the broadband shaping laser with one type Ⅰ doubling and one type Ⅱ tripling KDP crystals were analyzed quantificationally. The temporal shape and the spectrum distribution of the input shaping pulse and output third harmonic pulse were compared. The numerical calculation results were compared with those of temporal phase modulation （TPM） broadband shaping laser pulse. The results indicate that for the broadband shaping laser by CPS method, not only the relatively high third harmonic conversion efficiency can be realized, but also the temporal shape and the spectrum distribution keep nearly the same. The third harmonic conversion efficiency of CPS laser is higher than that of TPM laser.