Patent ID: 7362933
Filing Date: 2008-04-22
Classification: G02B

Abstract:
1. An optical branching unit comprising: a holding substrate which holds an optical branch structure which branches a light beam; an input waveguide which guides a light beam from outside of the holding substrate to the optical branch structure, the input waveguide having an end-face at which the light beam is inputted to the input waveguide; and first and second output waveguides which guide first and second branches of the light beam branched at the optical branch structure to outside of the holding substrate, each of the first and second output waveguides having an end-face from which the first and second branches are outputted from the first and second output waveguides, respectively; wherein a height of the end-face of the input waveguide in a direction perpendicular to a surface of the holding substrate that holds the optical branch structure is larger than a width of the end-face of the input waveguide in a direction along said surface of the holding substrate in a plane orthogonal to an input direction of the light beam to the input waveguide; wherein a width of the end-face of the first output waveguide in said direction along said surface of the holding substrate is longer than a height of the end-face of the first output waveguide in said direction perpendicular to said surface of the holding substrate, and a width of the end-face of the second output waveguide in said direction along said surface of the holding substrate is longer than a height of the end-face of the second output waveguide in said direction perpendicular to said surface of the holding substrate.