Self-compression of femtosecond pulses in argon with a power close to the self-focusing threshold  

作　　者：陈晓伟 曾志男 戴君 李小芳 李儒新 徐至展 

机构地区：[1]State Key Laboratory of High Field Laser Physics, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences

出　　处：《Chinese Physics B》2008年第5期1826-1832,共7页中国物理B（英文版）

基　　金：supported by the National Basic Research Program of China (Grant No 2006CB806000);the National Natural Science Foundation of China (Grant Nos 60578049 and 10523003);the Science and Technology Commission of Shanghai Municipality of China (Grant No 07JC14055)

摘　　要：Self-compression of femtosecond pulses in noble gases with an input power close to the self-focusing threshold has been investigated experimentally and theoretically. It is demonstrated that either multiphoton ionization （MPI） or space-time focusing and self-steepening effects can induce pulse shortening, but they predominate at different beam intensities during the propagation. The latter effects play a key role in the final pulse self-compression. By choosing an appropriate focusing parameter, action distance of the space-time focusing and self-steepening effects can be lengthened, which can promote a shock pulse structure with a duration as short as two optical cycles. It is also found that, for our calculation cases in which an input pulse power is close to the self-focusing threshold, either group velocity dispersion （GVD） or multiphoton absorption （MPA） has a negligible influence on pulse characteristics in the propagation process.Self-compression of femtosecond pulses in noble gases with an input power close to the self-focusing threshold has been investigated experimentally and theoretically. It is demonstrated that either multiphoton ionization （MPI） or space-time focusing and self-steepening effects can induce pulse shortening, but they predominate at different beam intensities during the propagation. The latter effects play a key role in the final pulse self-compression. By choosing an appropriate focusing parameter, action distance of the space-time focusing and self-steepening effects can be lengthened, which can promote a shock pulse structure with a duration as short as two optical cycles. It is also found that, for our calculation cases in which an input pulse power is close to the self-focusing threshold, either group velocity dispersion （GVD） or multiphoton absorption （MPA） has a negligible influence on pulse characteristics in the propagation process.

关 键 词：nonlinear propagation SELF-FOCUSING SELF-COMPRESSION 

分 类 号：O437[机械工程—光学工程]