Highly efficient (GaAl)As buried-heterostructure lasers with buried optical guide

Abstract

A new buried-heterostructure laser with a buried optical guide has been developed. A threshold current around 20 mA and a differential quantum efficiency as high as 85% are obtained under cw operation. This results in highly efficient laser operation, i.e., 35% power conversion efficiency at an optical output of 15 mW per facet, at which no degradation is observed over 3000 h at room temperature. Stable lowest-order transverse mode and nearly isotropic laser beam (∼25°×35°) are obtained. Second-order harmonic distortion is 55–65 dB below the fundamental level for 30% modulation with a 100-MHz sinusoidal signal at 5 mW.