Solitons in dispersion-managed mode-locked lasers

The dynamics and propagation of ultrashort optical pulses generated in mode-locked lasers are investigated. The mode locking process depends crucially on the gain and loss mechanisms inside the cavity. Analytical models are introduced that include dispersion management and gain-loss terms with energy and power saturation. Comparisons of the pulse dynamics with previously well-known models are discussed. Stable soliton solutions are found for wide ranges of the parameters; the only significant requirement being sufficient gain in the system. The evolution of the system “locks” into the pure soliton solutions obtained independently with mode finding algorithms. Such solutions can be viewed as soliton wave attractors. Finally, it is shown that these solutions satisfy an asymptotic averaged system and can be approximated by elementary, Gaussian-type, functions.