提出了一种啁啾补偿群速色散的倍频方法, 通过向入射基频光引入合适的初始啁啾, 让其与色散相互作用, 以实现对基频光脉冲宽度的主动控制, 提高转换效率。研究结果表明, 这种方法能显著地提高倍频转换效率, 以氘含量12.6％(摩尔百分比)的KD*P晶体对脉宽30 fs, 中心波长为1.053 μm的宽带基频光的折返点匹配宽带二倍频过程为例, 当基频光转换极限位置处于晶体中心时, 能取得最佳的啁啾补偿效果, 转换效率可提高近22％。进一步研究了转换效率和转换带宽与晶体长度的关系。

A novel second-harmonic generation scheme is proposed to compensate group velocity dispersion effects. In the scheme, a proper pre-chirp is introduced to the fundamental harmonic pulse to interact with dispersion, actively control its pulse width and raise the conversion efficiency. The result shows that the method improves the conversion efficiency of high harmonic greatly. For KD*P crystal with 12.6% deuterium, at the retracing point of phase matching, the conversion efficiency of the fundamental harmonic reaches the top at the crystal center, nearly 22%, and the optimal chirp compensation is obtained, for pulse width of 30 fs and central wavelength of 1053 nm. The relationship of conversion efficiency, conversion bandwidth and the crystal length is also studied.