Title :
Oxide-confined laser diodes with an integrated spot-size converter
Author :
De Mesel, Kurt ; Verstuyft, Steven ; Moerman, Ingrid ; Van Daele, Peter ; Baets, Roel
Author_Institution :
INTEC, Gent, Belgium
Abstract :
We report a new technique for the monolithic integration of a GaAs-based InGaAs-GaAs strained quantum-well laser and a spot-size converter (SSC) to improve the fiber coupling characteristics. The selective wet oxidation of AlGaAs is used to simplify the fabrication scheme of the component to a single planar epitaxial growth step and one conventional noncritical etch. This approach also allows us to avoid the photolithography of narrow features. An excellent reproducibility of the fabrication scheme was found. The integrated SSC exhibits very low transformation losses and a low beam divergence of 7.5°×13.5°. The coupling efficiency to a 980-nm single-mode fiber is improved from -6.34 dB for a reference laser to -1.49 dB for the tapered device. The -1-dB alignment tolerance is ±1.5 μm in the transverse direction and ±1.6 μm in the lateral direction, respectively.
Keywords :
III-V semiconductors; gallium arsenide; indium compounds; integrated optoelectronics; laser beams; optical fabrication; optical fibre couplers; oxidation; quantum well lasers; 980 nm; AlGaAs; GaAs-based InGaAs-GaAs strained quantum-well laser; InGaAs-GaAs; fabrication scheme; fiber coupling characteristics; integrated optics; integrated spot-size converter; lateral direction; low beam divergence; monolithic integration; noncritical etch; oxide-confined laser diodes; reference laser; selective wet oxidation; single planar epitaxial growth step; single-mode fiber; spot-size converter; tapered device; Diode lasers; Epitaxial growth; Lithography; Monolithic integrated circuits; Optical coupling; Optical device fabrication; Oxidation; Quantum well lasers; Reproducibility of results; Wet etching;
Journal_Title :
Selected Topics in Quantum Electronics, IEEE Journal of
DOI :
10.1109/JSTQE.2002.806673