This paper reports on a novel pair of microlens arrays (MLA's) for efficient coupling of the high aspect ratio optical beam emitted by high-power laser diode linear arrays (also referred to as laser diode bars) into the core of multimode optical fibers. These novel MLA's overcome the limitations observed when using high fill factors laser diode bars. The MLA designs are described. Results from modelling work show good coupling performances for laser diode bars with fill factors up to 75%. The technique for fabricating the complex surface profiles of the MLA's is discussed. Masters are first fabricated and MLA's are then replicated, so that volume production at low cost can be envisioned. The fabricated MLA's have been used for reshaping and fiber coupling the output of a 10-mm laser diode bar. An efficiency of 74% has been obtained when coupling into an optical fiber having a core diameter of 400 μm and a numerical aperture of 0.22.

Date Published: 15 February 2006
PDF: 10 pages
Proc. SPIE 6104, High-Power Diode Laser Technology and Applications IV, 61040R (15 February 2006); doi: 10.1117/12.655311

Published in SPIE Proceedings Vol. 6104:
High-Power Diode Laser Technology and Applications IV
Mark S. Zediker, Editor(s)