Self-consistent analysis of thermal far-field blooming of broad-area laser diodes

High-power broad-area laser diodes often suffer from a widening of the lateral (slow axis) far-field with increasing current, called thermal blooming, which is mainly caused by the non-uniform self-heating of the laser and has been studied for several decades. This paper presents the first self-consistent electro-thermal-optical simulation and analysis of such thermal blooming. Using a real InGaAs/GaAs broad-area laser as an example, a 900A/cm2 higher current density is shown to lead to only 0.5K stronger lateral temperature drop inside the ridge waveguide but to a one degree wider slow axis far field. Small non-thermal blooming is also observed.