Title :
Design and realization of a 1.55-μm patterned vertical cavity surface emitting laser with lattice-mismatched mirror layers
Author :
Gebretsadik, Herte ; Qasaimeh, Omar ; Jiang, Hongtao ; Bhattacharya, Pallab ; Caneau, Catherine ; Bhat, Rajaram
Author_Institution :
Dept. of Electr. Eng. & Comput. Sci., Michigan Univ., Ann Arbor, MI, USA
fDate :
12/1/1999 12:00:00 AM
Abstract :
It is possible to grow defect-free strained layers on patterned substrates (mesas or grooves) up to thicknesses far exceeding the critical thickness. Defect nucleation and propagation are inhibited in such growth. We have exploited this property to propose a novel InP-based 1.55-μm vertical cavity surface emitting lasers (VCSEL´s). Careful photoluminescence and transmission electron microscopy (TEM) studies have confirmed that there are no propagating defects in the GaAs/AlxGa1-xAs distributed Bragg reflector (DBR) grown on the patterned InP-based heterostructures, specifically in the multiquantum-well (MQW) region. Lasers were designed with InP/InGaAsP bottom mirrors, InAlAs-oxide current confinement and short-stack GaAs/Al xOy top DBR mirrors. An optimal reflectivity and a maximum wall plug efficiency are determined analytically for this structure. In addition, a theoretical analysis of the modulation response of this device is performed using a rate equation model. Both analyzes show the potential of such a device for implementation in practical designs where high power and modulation bandwidth are required. Lasers with 8-40 μm diameter have been fabricated and characterized. A threshold current of 5 mA is observed at 15°C for an 8 μm diameter device; and up to 60 μW of light output is recorded
Keywords :
III-V semiconductors; distributed Bragg reflector lasers; electro-optical modulation; gallium arsenide; gallium compounds; indium compounds; infrared sources; laser mirrors; laser transitions; molecular beam epitaxial growth; quantum well lasers; reflectivity; semiconductor growth; surface emitting lasers; 1.55 mum; 1.55-μm patterned vertical cavity surface emitting laser; 15 C; 5 mA; 60 muW; 8 mum; 8 to 40 mum; AlGaAs; GaAs; GaAs/AlxGa1-xAs distributed Bragg reflector; InAlAs-oxide current confinement; InGaAsP; InGaAsP MQW VCSEL lasers; InP; InP-based 1.55-μm vertical cavity surface emitting lasers; InP/InGaAsP bottom mirrors; MBE growth; MQW region; TEM; VCSEL; critical thickness; defect nucleation; defect-free strained layers; grooves; lattice-mismatched mirror layers; light output; maximum wall plug efficiency; mesas; modulation bandwidth; modulation response; optimal reflectivity; patterned InP-based heterostructures; patterned substrates; photoluminescence; propagating defects; rate equation model; short-stack GaAs/AlxOy top DBR mirrors; threshold current; transmission electron microscopy; Distributed Bragg reflectors; Gallium arsenide; Laser theory; Mirrors; Optical propagation; Photoluminescence; Quantum well devices; Surface emitting lasers; Transmission electron microscopy; Vertical cavity surface emitting lasers;
Journal_Title :
Lightwave Technology, Journal of
