在无啁啾激光脉冲的非线性压缩过程中,基于级联倍频机制,对影响脉冲压缩的敏感因素——晶体位相失配量进行了理论分析和实验验证。当入射基频激光(即1ω光,波长为800nm,脉宽为278fs)进入I类二倍频β-BaB2O4(BBO)晶体后,随着晶体位相失配量的增加,基频光的输出脉宽先降后升,这种趋势可总结为“U”字形非线性变化;当位相失配量为40mm-1时,脉宽缩至最小,此时脉宽压缩比最大。 In the nonlinear compression process without chirped laser pulse, the mismatch of crystal phase, which is the sensitive factor of pulse compression, was theoretically analyzed and verified by experiments based on the cascade frequency doubling mechanism. When the incident fundamental frequency laser (ie, 1ω light, the wavelength of 800nm, the pulse width of 278fs) into Class I double-frequency β-BaB2O4 (BBO) crystal, as the crystal phase mismatch increases, the output of the fundamental frequency light pulse When the phase mismatch amount is 40mm-1, the pulse width shrinks to the minimum, and the pulse width compression ratio is the largest at this time.