Passive mode locking in the presence of group velocity dispersion and self-phase modulation

Group velocity dispersion and self-phase modulation can be serious sources of pulse distortion in nonlinear optical devices designed to operate in the femtosecond region.1 We examine the problem of passive mode locking, where, in addition to the conventional mechanisms of saturable gain and saturable absorption, group velocity dispersion and self-phase modulation also contribute significant shaping of the mode-locked pulses.