Nonlinear Dynamics in Semiconductor Lasers 2023 - Abstract
Koch, Elias
Active mode-locking (AML) consists in generating pulses via direct modulation of the gain. It allows to directly modify the pulse shape and its repetition rate by changing the parameters of the modulation [1]. Most analysis of AML dynmaics have been based upon the Haus master equation, which accomodate for the regimes of small gain and losses per round-trip [2]. In this work we propose the use of the delay-differential equation model [3] with active modulation of the cavity losses. We perform a bifurcation analysis with parameters typical of semiconductor lasers in which the round-trip gain is not small. In particular, we found out that the solution branches corresponding to higher order Hermite-Gauss modes in a modulated potential can interact leading to a complex scenario. Furthermore, by performing a multiple time-scale analysis close to the lasing threshold, we derive a normal form which shows a good qualitative agreement with the original time-delayed model. Finally, we discuss the limit of slow gain that would correspond to an Erbium-Doped Fiber Amplifier (EDFA) regime.
[1] D.I. Kuizenga, and A. Siegman. IEEE Journal of Quantum Electronics 6.11 (1970): 694-708.
[2] A.M. Perego, et al. Nature communications 11.1 (2020): 311.
[3] A. Vladimirov, and D. Turaev. Physical Review A 72.3 (2005): 033808.