Publications

Design considerations for multi-fiber injection

Thomes, William J.; Dickey, Fred M.

Applications requiring injection of a high-power multimode laser into multiple fibers with equal energies, or specific energy ratios, provide unique design challenges. As with most all systems, engineering trades must balance competing requirements to obtain an optimal overall design. This is particularly true when fabrication issues are considered in the design process. A few of these competing design requirements are discussed in this conceptually simple system. This fiber injection system consists of three components; a refractive beam homogenizer, a diffractive beamsplitter, and a fiber array. We show the design process, starting with first-order design, for an example fiber injection system that couples a high-power YAG laser into seven fibers. Design goals include high efficiency, good beamsplitting uniformity, compact overall size, maximum mode filling of the fibers, and low cost of fabrication and assembly.