Abstract

The performance of (Al)GalnP visible light emitting semiconductor lasers has significantly improved over the last few years as the result of the introduction of strained quantum well (SQW) layers in the active region.¹ Grown-in strain modifies the valence subband structure which results in a reduced density of states and an improved symmetry of states at the valence band maximum. Both lead to a considerable reduction in the threshold current density of the semiconductor laser. We have fabricated by low-pressure organometallic vapour phase epitaxy (LP-OMVPE) 1% compressively strained single QW broad-area lasers with a threshold current density of 240 A/cm². The lasing wavelength is 675 nm. Gain guided 7 μm × 300 μm stripe lasers have threshold currents of 24 mA at room temperature and are lasing beyond 100°C. Lifetests of 4 different wafers at 70°C and 4 mW output power shows a projected median lifetime of 70,000 hours which demonstrates the excellent reliability of SQW visible lasers.

© 1994 IEEE