Robust Holographic-Couplers for High-Power Fiber Laser Array

A chirped grating is made in a thin film layer or a glass layer for producing a holographic optical element within the layer well suited for use as an optical coupler for coupling side fired laser light into optical fibers for laser light pumping of optical fibers with the grating made in the layer by generating interference fringes burned into the layer with interference fringes created from interfering a reference laser beam with a plurality of convergent laser beams from respective lenses of an array of lenses.