Mechanism of pulse shaping in femtosecond lasers based on the high-order soliton

The mechanism of pulse shaping in Kerr-lens mode-locking Ti:sapphire lasers is investigated. Considering the balanced interaction between self-phase m odulation, introduced by Kerr effect in Ti:sapphire, and group-velocity dis persion provided by prism-pair, pulse-splitting reflected in the intensity autocorrelation trace and pulse-compression display that the pulses outputt ing from different positions in laser cavity have different durations. We h ave concluded that the solitonlike pulse shaping that results from the comp etition between intracavity self-phase modulation within the Ti:S and negat ive group-velocity dispersion play dominant role in pulse evolution in Kerr -lens mode-locking lasers. (C) 2000 Elsevier Science Ltd. All rights reserv ed.