Investigation of locked operation in a system of two passively mode-locked semiconductor lasers under weak lateral coupling

Abstract

We study theoretically the operation of two semiconductor passively mode-locked lasers laterally coupled through evanescent fields. The investigation is carried out using a time domain traveling wave numerical model for two-section lasers (gain and absorption) enhanced to include weak mutual coupling. The study of the coupled system shows that although the operation is dominated mostly by instabilities and amplitude modulated pulse trains, under specific conditions, stable mode locking with low intensity noise and time-synchronized pulses emerges. The influence of operational and geometrical parameters on the coupled dynamics is identified and discussed.