Title :
Low-loss low-confinement GaAs-AlGaAs DQW laser diode with optical trap layer for high-power operation
Author :
Buda, M. ; van der Vleuten, W.C. ; Iordache, Gh. ; Acket, G.A. ; van de Roer, T.G. ; van Es, C.M. ; van Roy, B.H. ; Smalbrugge, E.
Author_Institution :
Fac. of Electr. Eng., Eindhoven Univ. of Technol., Netherlands
Abstract :
A low-confinement asymmetric GaAs-AlGaAs double-quantum-well molecular-beam-epitaxy grown laser diode structure with optical trap layer is characterized, The value of the internal absorption coefficient is as low as 1.4 cm/sup -1/, while keeping the series resistance at values comparable cm with symmetrical quantum-well gradient index structures in the same material system. Uncoated devices show COD values of 35 mW/μm. If coated, this should scale to about 90 mW/μm. The threshold current density is about 1000 A/cm2 for 2-mm-long devices and a considerable part of it is probably due to recombination in the optical trap layer. Fundamental mode operation is limited to 120-180 mW for 6.5-μm-wide ridge waveguide uncoated devices and to 200-300 mW for 13.5-μm-wide ones, because of thermal waveguiding effects. These values are measured under pulsed conditions, 10 μs/l ms.
Keywords :
III-V semiconductors; absorption coefficients; aluminium compounds; gallium arsenide; gradient index optics; molecular beam epitaxial growth; optical losses; quantum well lasers; ridge waveguides; semiconductor growth; symmetry; waveguide lasers; 120 to 180 mW; 13.5 mum; 2 mm; 200 to 300 mW; 6.5 mum; COD values; GRIN; GaAs-AlGaAs; fundamental mode operation; high-power operation; internal absorption coefficient; low-loss low-confinement GaAs-AIGaAs DQW laser diode; molecular-beam-epitaxy grown laser diode structure; optical trap laye; optical trap layer; pulsed conditions; series resistance; symmetrical quantum-well gradient index structures; thermal waveguiding effects; uncoated devices; Absorption; Charge carrier processes; Diode lasers; Optical devices; Optical materials; Optical waveguides; Pulse measurements; Quantum well lasers; Radiative recombination; Threshold current;
Journal_Title :
Photonics Technology Letters, IEEE
