摘要
对超短强激光脉冲在CsLiB6O10 晶体中的群速失配进行了理论分析 ,采用傅里叶变换法推导超短脉冲二次谐波的耦合波方程。在I类相位匹配下数值计算了脉冲宽度 5 0fs的基波 5 32nm ,在CsLiB6O10 晶体长度为 0 .5mm时产生二次谐波 (2 6 6nm)的群速延迟量约 10 0fs ,并且随着晶体长度的增长 ,二次谐波的脉冲宽度几乎线性展宽。并得到了群速失配量Δβ( 2 )1=2 2 6 .2 4 3fs/mm ,低阶和二阶群速色散系数分别为 β( 2 )2 =2 10 .12 0fs2 /mm ,β( 3 )2 =6 5 .5 87fs3 /mm。其结果表明由于群速延迟和群速色散导致了谐波脉宽展宽和形变。
Group velocity mismatching and group velocity dispersion of fs laser pulse in CsLiB 6O 10 crystal are analyzed. The coupled equations of ultra-short pulse SHG are deduced by Fourier transform. The second harmonic pumped by 532 nm, 50 fs fundamental wave through CLBO is simulated numerically. The results show that the group velocity delay of second harmonic is about 100 fs at 266 nm through 0.5 mm lengths CsLiB 6O 10 and the second harmonic shape is widened linearly with the increase of crystal length. The group velocity mismatching Δβ (2) 1= 226.243 fs/mm, and lowness and second order group velocity dispersion β (2) 2=210.120 fs2/mm, β (3) 2=65.587 fs3/mm are reported for second harmonic on CsLiB 6O 10 crystal. The results indicate that group velocity mismatching and group velocity dispersion lead to the widening and defomation of the harmonic.
出处
《光学学报》
EI
CAS
CSCD
北大核心
2004年第9期1249-1252,共4页
Acta Optica Sinica
基金
北京市教委基金 (Km2 0 0 310 0 0 5 0 2 2 )资助课题。
