Title :
Low-divergence laser structures for cost-effective fiber coupling applications
Author :
Gough, Oliver P. ; Buckley, U. ; Corbett, B. ; Lambkin, J.D.
Author_Institution :
Dept. of Electr. & Electron. Eng, Cork Inst. of Technol., Ireland
Abstract :
We report on the design of lasers using waveguide engineering to achieve low divergence emission with high butt-coupling efficiency to single-mode (SMF) and multimode fiber (MMF). A tolerant design principle is introduced for achieving low-divergence normal to the junction using a single epitaxial growth step. The design method is compatible with a wide range of material systems and is demonstrated using a 980-nm laser structure. The full-width half-maximum of the beam is reduced from more than 32/spl deg/ to 21/spl deg/. Direct butt-coupling losses are improved from -10 dB to near -3 dB for ridge waveguide to SMF coupling, while broad area devices coupled to MMF showed coupling efficiencies of >75%.
Keywords :
laser modes; laser transitions; optical design techniques; optical fibre couplers; optical fibre losses; ridge waveguides; semiconductor lasers; waveguide lasers; 75 percent; 980 nm; 980-nm laser structure; cost-effective fiber coupling applications; coupling efficiencies; design method; direct butt-coupling losses; full-width half-maximum; high butt-coupling efficiency; laser diodes; low divergence emission; low-divergence; low-divergence laser structures; multimode fiber; ridge waveguide; single epitaxial growth step; single-mode fiber; tolerant design principle; waveguide engineering; Design engineering; Design methodology; Epitaxial growth; Fiber lasers; Laser beams; Molecular beam epitaxial growth; Optical coupling; Optical design; Optical materials; Waveguide lasers;
Journal_Title :
Selected Topics in Quantum Electronics, IEEE Journal of
DOI :
10.1109/2944.883370
