Direct observation of pulse propagation of femtosecond laser in glass with femtosecond time-resolved optical polarigraphy (FTOP)

Modulated pulse shapes in a dispersive transparent material due to group-velocity dispersion, self-phase modulation, and self-focusing induced by a femtosecond laser light were observed directly with a femtosecond time-resolved imaging technique probing the induced instantaneous birefringence.