Apparatus and method for encapsulation of an optical fiber splice

This invention relates, generally, to optical fiber couplings and, more specifically, to optical fiber splices between double clad and single mode optical fibers. An optical fiber splice apparatus has a covering that surrounds the splice between two optical fibers, and conducts residual pump energy in the fiber claddings away from the splice. This prevents the residual light from reaching components, such as plastic buffers, that are susceptible to failure from excess light absorption. The apparatus may use an optical epoxy covering that surrounds adjoining portions of both fibers, and that has a refractive index higher than that of the outermost fiber claddings. The covering may be surrounded by a glass capillary that is transparent to the residual light, and that conducts light from the covering further away from the splice. The capillary may be mounted in a metal housing by an adhesive epoxy that is transparent to the residual pump light, and can conduct light to an inner surface of the housing, which may be light absorbent to the wavelength range of the residual pump light. The splice apparatus may be part of an overall optical gain device such as a fiber laser or fiber optic amplifier.