Title :
Optimisation of λ=850 nm hybrid-mirror vertical-cavity surface-emitting laser with 37 μA threshold current
Author :
Langenfelder, T. ; Grothe, H.
Author_Institution :
Lehrstuhl fur Allgemeine Elektrotech. und Angewandte Elektronik, Tech. Univ. Munchen, Germany
fDate :
2/1/2000 12:00:00 AM
Abstract :
A vertical-cavity surface-emitting laser (VCSEL) structure is optimised for low threshold current. The cavity comprises a GaAlAs bottom DBR with a dielectric SiO2-Si3N4 output mirror on top. The asymmetrical active region consists of GaAs-QWs, emitting at 850 nm. Selective lateral oxidation is applied to the p-side AlAs layer for current confinement. With the realised structure, a record low threshold current for selectively oxidised, hybrid Ga(Al)As lasers of Ith=37 μA at an oxide-aperture diameter of Øap=4.9 μm is achieved. The observed multimode emission spectrum is analysed using a simplified theoretical model for the transverse-mode guiding, and first experimental results of a redesigned VCSEL structure with single-mode operation at similar aperture diameters are presented
Keywords :
distributed Bragg reflector lasers; infrared sources; laser mirrors; laser modes; laser theory; laser transitions; optimisation; quantum well lasers; semiconductor device models; surface emitting lasers; μA threshold current; 37 muA; 4.9 mum; 850 nm; 850 nm hybrid-mirror vertical-cavity surface-emitting laser; GaAlAs; GaAlAs bottom DBR; GaAs-QWs; SiO2-Si3N4; VCSEL; aperture diameters; asymmetrical active region; dielectric SiO2/Si3N4 output mirror; low threshold current; multimode emission spectrum; oxide-aperture diameter; redesigned VCSEL structure; selective lateral oxidation; single-mode operation; transverse-mode guiding;
Journal_Title :
Optoelectronics, IEE Proceedings -
DOI :
10.1049/ip-opt:20000318
