High-gain and low-threshold InAs quantum-dot lasers on InP

Abstract

InAs quantum-dot (QD) laser structures are grown on (113)B-oriented InP substrate by gas-source molecular-beam epitaxy. Following an optimized growth procedure, a high density of 1.1 × 10 11 cm − 2 of uniformly sized QDs is achieved. Broad-area lasers containing three stacked QD layers have been realized and tested. Laser emission on the ground-state transition ( λ = 1.59 μ m ) is obtained at room temperature (RT), at a threshold current density as low as 190 A ∕ cm 2 . Ground-state modal gain and transparency current density is measured to be 7 cm − 1 and 23 A ∕ cm 2 per dot layer. Ground-state laser emission is also demonstrated from low temperature (100 K, J th = 33 A ∕ cm 2 ) to high temperature (350 K), exhibiting an insensitive threshold in the [100, 170] K range, and a 55 K characteristic temperature at RT.