Delay differential equations enriched with nonlinear gain compression for passively mode-locked semiconductor lasers

Abstract

Non-linear gain compression is well-known to play an important role in the dynamics of short-pulse generation and propagation in semiconductor lasers. Here, a previously reported delay differential equation model for passively mode-locked semiconductor lasers is enhanced with nonlinear gain compression terms in gain and absorber sections. We report the modified model equations and show the impact in gain/absorption dynamics with respect to the original model. In addition, we perform an extended comparison between the enriched delay differential equation model applied on a ring cavity and a travelling wave model applied on an equivalent Fabry-Perot cavity, highlighting the limits of quantitative and qualitative agreement between the two approaches.