Soliton-like pulses generated by mode-locked lasers with either slow or fast saturable absorber response

The passively mode-locked laser [1, 2, 3, 4, 5] is a much-studied device in recent years. Ultra-short pulse generation in laser systems makes use of a variety of schemes including figure-of-eight fiber laser design [1], fast saturable absorbers [4], additive pulse mode-locking [5] and nonlinear polarization rotation [6, 7]. The use of a semiconductor saturable absorber mirror with relatively slow response time and even slower recovery time has been suggested for a passively mode-locked soliton laser [8]. Experimental verification of this possibility has been reported in [9]. In the present work, we present an exact soliton-like solution for pulses generated by a solid-state laser with a semiconductor saturable absorber with slow recovery time.