Propagation of femtosecond light pulses in water is investigated. By changing input power from slightly above to highly above threshold for self-focusing, it is shown that either group velocity dispersion (GVD) or multi-photon ionization (MPI) and multi-photon absorption (MPA) may arrest the collapse. When MPI and MPA dominate the propagation, the pulse can be self-compressed to a few optical cycles. In spectral domain, MPI alone induces a strong blue shift. MPA can restrain this strong blue shift.
© 2007 Chinese Optics Letters
(140.0140) Lasers and laser optics : Lasers and laser optics
(190.7110) Nonlinear optics : Ultrafast nonlinear optics
(320.2250) Ultrafast optics : Femtosecond phenomena
(320.5520) Ultrafast optics : Pulse compression
Feng Xu, Jiansheng Liu, Ruxin Li, and Zhizhan Xu, "Pulse compression and supercontinuum at different powers of femtosecond pulses in water," Chin. Opt. Lett. 5, 490-492 (2007)