The role of amplitude and phase shaping in the dispersive-pulse regime of a passively mode-locked dye laser

The relative contributions of nonlinear amplitude and phase modulation in determining the shape and duration of a sub-100-fs pulse generated by a colliding-pulse mode-locked dye laser are examined. A phenomenological numerical model is developed that accounts consistently for the finite bandwidth of the saturable gain and absorbing media. The results for the model are compared with the experimentally measured amplitude and phase of 60-fs pulses from a laser operated in the dispersive (i.e., nonsoliton) regime. Good agreement is found with the measured pulse amplitude temporal asymmetry and with the measured chirp.<
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