Abstract

GaN and related compounds are challenging materials for UV and visible semiconductor lasers. While stimulated emission from photopumped GaN-based structures was relatively easy to achieve [1], only very recently has the first diode laser been announced [2]. In spite of their importance for design and further studies of GaN-based lasers, investigations of radiative recombination and emission processes in GaN are still at their infancy. In this paper, we consider radiative processes in GaN and calculate the radiative recombination coefficient and optical gain as functions of excess carrier density and injection current density. We then predict the theoretical limit for the threshold current density in optimized double-heterostructure (DH) lasers emitting in the near-UV spectral range.

© 1996 Optical Society of America