Ultrafast Nonequilibrium Carrier Dynamics in Semiconductor Laser Mode-Locking

This chapter addresses the question of how ultrafast microscopic dynamics of the carriers within their respective bands influences mode-locking stability, stability, and robustness of the final pulse that emerges, induces a transient nonlinear refractive index, allows for a mode locked pulse spectrum that is wider than the net gain region, and sets limits on the shortest possible achievable pulses. It provides an overview of the theoretical modeling of mode locking in Vertical external-cavity surface-emitting lasers (VECSELs) with a semiconductor external saturable absorber mirrors (SESAM), as well as microscopic modeling of graphene saturable absorbers (GSAM). The chapter also provides an overview of the pulse propagation and microscopic theory is given with additional background information. It explores the domain modeling, gain region modeling, and some additional background and considers the numerical results for mode-locking VECSELs, with an analysis of SESAM and GSAM properties.