Patent ID: 7116867

Claim:
A multiple split optical waveguide including a substrate having a plurality of waveguide paths defined therein in a tree configuration, said waveguide paths including an input waveguide path extending along a central axial line, a plurality of stages of branch parts and branch waveguide paths extending from said branch parts, said branch waveguide paths including output waveguide paths extending from branch parts of a final stage, wherein: a branch waveguide path at an output end of a branch part of a first stage extends to an input end of a branch part of a second stage, the input end of the branch part of the second stage defining a non-zero acute angle with respect to the central axial line, wherein light entering the input end of the branch part of the second stage is split and is output from a plurality of branch wave guide paths extending from the branch part of the second stage, and a branch waveguide path at an input end of an outermost branch part of an n-th stage defines an outward inclination angle with respect to the central axial line which is equal to or greater than a corresponding outward inclination angle defined by a branch waveguide path at an input end of an outermost branch part of an (n+1)-th stage with respect to the central axial line, n being an integer equal to or greater than two; wherein the input waveguide path extends along the central axial line to the branch part of the first stage.