Patent ID: 7532792
Filing Date: 2009-05-12
Classification: G02B,H01S

Abstract:
1. An optical coupler for coupling light from at least two input fibers into one output fiber, the optical coupler comprising a) an input section comprising at least two input fibers, which are bundled over a bundling-length and having an output end face at one end of the bundling-length; and b) an output section having an input end face, said output section further comprising an output fiber comprising a confining region for confining light propagated in said input fibers and a surrounding low index cladding region comprising down-doped silica; wherein said output end face of said input section is optically coupled to said input end face of said output section, the output fiber comprises an air-cladding for confining light surrounding said confining region at least over part of its longitudinal extension, and at least said confining region of said output fiber is tapered down from a first cross sectional area at said input end face to a second, smaller cross sectional area over a tapering-length of said output fiber.