Inverse Thermal Lens Effects on the Far-Field Blooming of Broad Area Laser Diodes

Abstract

High-power broad-area laser diodes often suffer from a widening of the lateral far-field with increasing current (slow-axis far-field blooming). This effect mainly originates in self-heating that generates a lateral thermal lens in the active region. Pedestal heat sinking was recently shown to mitigate the far-field blooming. In this letter, utilizing self-consistent electro-thermal optical simulations, we analyze such a far-field improvement and link it to the formation of an inverse thermal lens. At high injection current, the inverse thermal lens is shown to weaken high-order lateral modes and to even narrow the slow-axis far-field.