DISTORTION OF SELF-INDUCED-TRANSPARENCY SOLITONS AS A RESULT OF SELF-PHASE MODULATION IN ION-DOPED FIBERS

The temporal envelope profile and the phase of a steady-state pulse pr opagating through a resonant medium in the presence of nonresonant non linearity are derived. The formation of solitonlike pulses takes place as a result of the balance of the self-phase modulation generated by nonresonant nonlinearity and the nonlinear resonant group-velocity dis persion induced by the self-induced-transparency effect in a resonant medium. Self-phase-modulation action leads to distortion of the pulse when its power and inverse duration exceed the critical values P(c)r a nd tau(c)r(-)1. We show the destructive role of self-phase modulation in the case of self-induced-transparency values transparency pulse gen eration in a laser with erbium-doped fiber as an intracavity coherent absorber. (C) 1995 Optical Society of America