<title>Beam shaping and fiber coupling of high-power diode laser arrays</title>

Abstract

A technique for coupling the radiation of a high-power diode laser bar into one multimode fiber with high efficiency, easy alignment requirements and low manufacturing costs is demonstrated using a single fiber with 400 micrometers core diameter. The principal item of the fiber-coupling system is a pair of micro step-mirrors--a novel design for beam shaping. The overall efficiency from diode-laser to fiber is 71% with 20 W cw laser power through the fiber. Polarization and wavelength multiplexing renders the system scaleable to higher output power which makes it highly suitable for material processing and pumping of lasers.