Vertical-cavity surface-emitting quantum-dot laser with low threshold current grown by metal-organic vapor phase epitaxy

Abstract

Ground state lasing of electrically driven vertical-cavity surface-emitting lasers with a quantum-dot (QD) gain medium grown using metal-organic vapor phase epitaxy was realized. The devices use stacked InGaAs QD layers, placed in the field intensity antinodes of the cavity formed by selectively oxidized distributed Bragg reflectors. Devices with 3×3 QD layers demonstrate at 20°C a cw output power of 1.45mW at 1.1μm emission wavelength. The peak external efficiency was 45%, limited by lateral carrier spreading within the 4λ cavity and a reduction of the internal efficiency above 60°C. A minimum threshold current of 85μA was obtained from a device with a 1μm aperture.