GaAs-GaAlAs graded-index separate confinement heterostructure laser diodes selectively grown by molecular beam epitaxy on SiO₂-masked substrates

The GaAs-GaAlAs graded-index separate confinement heterostructure was grown selectively by molecular beam epitaxy on a SiO2-masked GaAs (100) substrate. The stripe windows on the SiO2 mask were 10 μm in width and were oriented along [011̄] direction. The laser diodes thus fabricated lased in a single longitudinal mode with a side mode suppression ratio of 95:1. Both the longitudinal mode and the single-lobe far-field pattern were stable up to 4Ith.