Strain compensated 1120 nm GaInAs/GaAs vertical external-cavity surface-emitting laser grown by molecular beam epitaxy

Abstract

We report on the development of high quality, strain compensated gain mirror for 1120 nm vertical external-cavity surface-emitting lasers (VECSELs). The gain mirror was grown by molecular beam epitaxy and comprised a total of six Ga 0.69In 0.31As quantum wells. The effect of the strain compensation has been assessed by measuring the curvature of the wafer and by mapping the photoluminescence to identify the non-emissive dark areas. We demonstrate that ∼91% strain compensation with GaAs 0.85P 0.15 is sufficient to remove the dark lines corresponding to areas with structural defects in the gain mirror structure. Rapid thermal annealing studies revealed that the strain compensation is efficient in preventing the appearance of dark lines even for samples that were annealed at temperatures as high as 700 °C for a considerable time. The strain compensated gain mirror was used to demonstrate a VECSEL emitting at 1120 nm.