Title :
Efficient power coupling from a 980-nm, broad-area laser to a single-mode fiber using a wedge-shaped fiber endface
Author :
Shah, Virendra S. ; Curtis, Lyn ; Vodhanel, Richard S. ; Bour, David P. ; Young, W.C.
Author_Institution :
Bell Commun. Res. Inc., Red Bank, NJ, USA
fDate :
9/1/1990 12:00:00 AM
Abstract :
A theoretical and experimental study of an efficient technique for coupling a broad-area laser to a single-mode fiber without the use of bulk optical components was carried out. The technique uses a wedge-shaped fiber endface to approximate a cylindrical lens action to correct for the phase mismatch between the curved laser beam wavefront and the planar fiber beam. A theoretical formula for the coupling efficiency in the absence of both angular and transverse misalignments is derived. By optimizing the wedge angle and the axial separation between the laser facet and the fiber endface, a maximum coupling efficiency of 47%, compared to 20% for the square endface, achieved, resulting in 15.2 mW of power in the single-mode fiber. The fabrication process consists of a simple polishing procedure requiring a wedge-shaped polishing tool and is highly reproducible
Keywords :
laser accessories; lenses; optical couplers; optical fibres; 15.2 mW; 47 percent; 980 nm; angular misalignments; axial separation; broad-area laser; coupling efficiency; curved laser beam wavefront; cylindrical lens action; efficient power coupling; fabrication process; laser facet; phase mismatch; planar fiber beam; polishing procedure; single-mode fiber; theoretical formula; transverse misalignments; wedge angle; wedge-shaped fiber endface; wedge-shaped polishing tool; Diode lasers; Erbium-doped fiber lasers; Fiber lasers; Laser beams; Laser excitation; Laser theory; Optical coupling; Optical fiber polarization; Power lasers; Pump lasers;
Journal_Title :
Lightwave Technology, Journal of
