Abstract

One major advantage of fiber lasers over solid state lasers is that they can be all fiber integrated making them rugged and compact. Up to now, the standard configuration for pumping a fiber laser consists of broad-stripe single-emitters delivering 5 to 10 W out of a 100 um fiber. These fibers are bundled with a 7-to-l or 19-to-l combiner. Recent advances in fiber coupled diode lasers lead up to 25 or even 40 W out of 100 um. A combiner, suitable for pumping a fiber laser with such pump modules, must be capable of handling up to 280 W in a 7-to-l configuration and 760 W in a 19-to-l configuration. The second requirement is that the loss of brightness from the input beam must be low. Commercially available couplers are, to our knowledge for the first time, characterized regarding their brightness conservation and tested up to a power level of more than 580 W of coupled power.

© 2007 IEEE