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

• 来源期刊: 中国物理B（英文版）
• 关键词: nonlinear propagation self-focusing self-compression
• 年，卷（期）: 2008,（5）
• 页码范围: 1826-1832
• 页数: 7页
• 语种: 英文

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 eases 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.