Systematics of Optical Gain in GaInN/GaN Laser Structures

Abstract

Optical gain and absorption of different laser-structures were measured and calculated in order to clarify the influence of internal fields on these properties. For the calculations a model is used that is based on the assumption of band-to-band transitions and includes the effect of piezoelectric fields. The experimentally found energy shifts between absorption and the onset of gain could be explained only through the presence of an internal field. The minimal threshold current densities for a double quantum well laser and for a well thickness of 2 nm were confirmed.