OPTICAL BRANCHING DEVICE

摘要

An optical branching device characterized in that a zone, which is in the upstream of an optical branching portion (22) where light is branched into two outgoing waveguides (25-1, 25-2), has a rectangular or noncircular sectional shape of a different aspect ratio, with the length in a direction along the face of a base (10) is defined shorter than that in a direction normal to the face of the base, and in that the outgoing ends (23-1, 23-2) of the outgoing waveguides are formed to have a rectangular or noncircular sectional shape of a different aspect ratio, with the length in a direction along the face of the base is defined longer than that in a direction normal to the face of the base.