Is noise a crucial factor in rate equation modeling of nonlinear dynamics in laser diodes?

Evaluation of the influence of laser noise on the precision of single-mode rate equations in modeling laser diode (LD) behavior is performed. The inclusion of Langevin noise sources in simulations is found to increase the relaxation damping significantly. This phenomenon explains the reported truncations of higher-order bifurcations leading to chaos and the enhancement of period-doubling when laser noise is taken into account in simulations. Numerical analysis of the nonlinear dynamics of directly-modulated LD is performed, and results show that laser noise has been mistaken as an important factor which enables an agreement between calculated and measured results to be achieved. Instead, simulations carried out to investigate the effect of current-dependent gain suppression on the nonlinear behavior of LD reveal that temperature plays an important role in modeling LD behavior. Hence, accurate electro-thermal modeling is critical in reproducing measured behavior of LD in simulations