High efficiency and low threshold current strained V-groove quantum-wire lasers

Abstract

Multi-quantum-wire strained lasers are reported in the Ga 1-xInxAs/Ga1-xAlxAs semiconductor material system with a minimum threshold current of 188 μA and maximum powers of ≊50 μW in continuous multimode operation at wavelengths of ≊980 nm and differential output of ≊0.5 μW/μA. The structures, fabricated by molecular-beam epitaxy, are self-aligned, self-isolated, and minimize electrical and optical losses. Internal quantum efficiencies are ≊83% and internal losses are ≊4.2 cm-1. Characteristic temperatures of ≊260 K, and an increase in threshold current and lasing wavelength under externally applied stress changing from compressive to tensile conditions, show that the major determinants of lasing threshold are density of states and optical losses.