基于级联倍频机制无啁啾激光脉宽随晶体位相失配量的非线性变化  

Nonlinear Pulse Width Change of Nonchirped Pulse Versus Crystal Mismatch by Cascaded Harmonic Generation

作　　者：李恪宇[1] 冯斌[1] 孙立[1,2] 向勇[1] 郭仪[1,2] 黄征[1,2] 孙志红[1] 李庆[1,2] 谢娜[1,2] 叶荣[3] 王晓东[1,2] 

机构地区：[1]中国工程物理研究院激光聚变研究中心,四川绵阳621900 [2]等离子体物理重点实验室,四川绵阳621900 [3]四川大学电子信息学院,四川成都610064

出　　处：《光学学报》2014年第12期217-221,共5页Acta Optica Sinica

基　　金：国家自然科学基金(11304293;11174258)

摘　　要：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。Based on the cascaded frequency-harmonic mechanism during the course of nonlinear compression of nonchirped laser pulse, the sensitive factor affecting the pulse compression of crystal phase mismatch is analyzed theoretically and validated experimentally. After the input fundamental pulse （namely, leo, 0.8-μm wavelength and 278-fs pulse width） propagates through the type I second harmonic generation 13-BaB2 04 （BBO） crystal, the leo output pulse width is shortened firstly and widened again with the increase of crystal phase mismatch. This trend can be summarized as the ＂U＂ grapheme nonlinear change. The output pulse width is shortened to the least value and the highest compression ratio of pulse width is obtained when the crystal mismatch is 40 mm 1.

关 键 词：非线性光学 级联倍频 自相位调制 附加相移 晶体位相失配量 脉宽压缩比 

分 类 号：O437.1[机械工程—光学工程]