Patent ID: 7817889
Filing Date: 2010-10-19
Classification: G02B

Abstract:
1. An optical waveguide structure comprising: a substrate having an upper planar surface formed with a first groove array and a second groove array which are longitudinally spaced from each other, each groove array including a plurality of anisotropically-etched V-shaped cross-sectional grooves extending longitudinally and arranged laterally relative to each other, said grooves being laterally spaced from each other via the upper planar surface and formed with submicron accuracy; and an optical waveguide made of polymer and integrally layered on the upper planar surface of the substrate between the first and second groove arrays; wherein the optical waveguide has a lower cladding directly layered on the upper planar surface of the substrate, and has a core on the lower cladding layered on the substrate so that, when optical fibers are supported and positioned on the grooves of the first and second groove arrays, the core of the optical waveguide becomes aligned with cores of the optical fibers at the same level in a vertical direction; wherein the optical waveguide is an optical waveguide formed by applying a polymer material for the lower cladding onto the upper planar surface of the substrate formed with the V-shaped cross-sectional grooves and applying a polymer material for the core onto the polymer material for the lower cladding, so that portions of the polymer material for the lower cladding intruding into the V-shaped cross-sectional grooves are depressed to pull the polymer material from the lower cladding around the V-shaped cross-sectional grooves, toward the V-shaped cross-sectional grooves, wherein, in order to allow light transmission between optical fibers positioned at the respective first and second groove arrays, the optical waveguide has at least one first port aligned with (a) groove(s) of the first groove array, and second ports aligned with grooves of the second groove array, the number of the second ports being greater than that of the first port(s); and wherein the grooves of each of the first groove array and the second groove array are arranged over the entire width of the optical waveguide structure at even intervals, and the intervals of the grooves of the first groove array are equal to those of the grooves of the second groove array so that the grooves of the first groove array include an aligned groove aligned with the first port, and a non-aligned groove arranged laterally adjacent to the aligned groove, the non-aligned groove being located out of alignment with any first ports of the core of the waveguide so that a thickness of the lower cladding at the first port is brought closer to that of the cladding at the second port.