Design of pumping system for high power fiber lasers

Based on beam characteristic of semiconductor lasers, The paper details a pumping system, which couples single LD to multimode with hyperboloid micro-lens at first, and then combines sixteen LD fiber coupled modules which with 2W output power to parallel pump fiber lasers which with fiber Bragg grating on each end by using a multimode coupler at each end. The total conversion efficiency of optical to optical is 40% and output power from fiber is 13W. Because this pumping system has merit of small volume, compact structure, replaced easy, long lifetime and high pumping efficiency, it more fits to end and side pumping for fiber lasers.