Patent ID: 7748910
Filing Date: 2010-07-06
Classification: G02B

Abstract:
1. An optical system comprising: a substrate; and an optical waveguide which is formed on the substrate and to which optical fibers are to be optically coupled; wherein the optical waveguide has a plurality of straight core portions which obliquely intersect each other, the substrate has positioning sections for positioning a plurality of optical fibers optically coupled to two or more of the plurality of the core portions, the positioning sections having grooves on which the respective optical fibers are supported, when the plurality of optical fibers are supported on the respective grooves, offsets between centers of the plurality of the core portions and respective centers of the plurality of the optical fibers coupled to the core portions are equal to or less than 5 μm, the substrate has a crystal axis, when supported on the respective grooves, at least one of the optical fibers is obliquely positioned relative to the crystal axis, the groove for the at least one of the optical fibers includes a plurality of sub-grooves respectively formed along a plurality of axes extending in a direction of the crystal axis, and the sub-grooves are continuously disposed and gradually shifted in a direction lateral to the crystal axis so that the sub-grooves are arranged along an optical axis of the at least one of the optical fibers to be obliquely disposed relative to the crystal axis, and the sub-grooves have the same depth from a surface of the substrate and are shaped so that, when the plurality of optical fibers are supported on the respective grooves, the optical axis of the at least one of the optical fibers obliquely disposed relative to the crystal axis will lie in a single plane parallel to the surface of the substrate.