In order to test power-handling at 1kW, a special splitter component had to be developed to make use of available
sources. A tapered fused-bundle (TFB) 1X7 splitter using a 1.00mm core diameter 0.22NA input fiber coupled to seven
400 micron core 0.22 NA output fibers was tested up to 860W at 976nm. Surface temperature rise was measured to be
less than 15°C with active heat sinking. The above results suggest that understanding the mechanisms of optical loss for
forward and backward propagating light in a TFB and the heat load that these losses generate is the key to producing
multi kW components, and demonstrates that reliable kW-level all fiber devices are possible.