US Patent 9871338 Pump combiner for multi-clad fibers

Disclosed herein is a fiber pump combiner, comprising, a multi-clad fiber comprising an outer cladding layer and an inner cladding layer, a plurality of tapered trenches formed in the inner cladding layer and a plurality of pump fibers, wherein the plurality of pump fibers are tapered and fused into corresponding ones of the plurality of tapered trenches.