PULSE SPLITTING IN A SELF-MODE-LOCKED TI-SAPPHIRE LASER

A femtosecond pulse generated from a self-mode-locked Ti:sapphire lase r was found to split into two or even three pulses. The time separatio n between these split pulses was found to depend on the pulse width. M ore interestingly, a slight disturbance could cause this time separati on to increase further, not continuously, but by a multiple of a time constant. The pulse splitting could be due to side-lobe pulse generati on by the separate action of the negative group-velocity dispersion an d self-phase modulation in the laser cavity.