Pulse shapes in a dispersive transparent material modulated by group-velocity dispersion, self-phase modulation, and self-focusing induced by a femtosecond laser light were observed directly with femtosecond time-resolved optical polarigraphy probing the induced instantaneous birefringence. The first observation of the state of femtosecond laser pulses about the interaction region inside the transparent bulk material indicated that the pulse propagation was accomplished with a multiple conelike structure that was hypothesized from a numerical simulation with an extended nonlinear Schrödinger equation.
© 2003 Optical Society of America
(140.3440) Lasers and laser optics : Laser-induced breakdown
(260.1440) Physical optics : Birefringence
(320.2250) Ultrafast optics : Femtosecond phenomena
(320.7100) Ultrafast optics : Ultrafast measurements
(350.5500) Other areas of optics : Propagation
Hiroshi Kumagai, Sung-Hak Cho, Kenichi Ishikawa, Katsumi Midorikawa, Masatoshi Fujimoto, Shin-ichiro Aoshima, and Yutaka Tsuchiya, "Observation of the complex propagation of a femtosecond laser pulse in a dispersive transparent bulk material," J. Opt. Soc. Am. B 20, 597-602 (2003)