Multi-peak spectrum of KML Ti : sapphire pulse

The multi-peak spectrum of Ti:sapphire pulses observed experimentally under ultra-broad bandwidth conditions (< 15 fs pulse length) has been explained theoretically. It is shown that the self-phase-modulation effect is equiva lent to the process of degenerate four-wave frequency-mixing. Based on this theoretical underpinning, the presence or absence of a multipeak spectrum provides a practical measure of whether the intracavity group-velocity-disp ersion is ideally compensated for or not.