Patent ID: 6865314

Claim:
An optical wavelength filtering apparatus, comprising: an input waveguide in a first plane; an output waveguide in a second plane; and, a resonant cavity in a third plane distinct from said first plane and said second plane and substantially parallel to said first plane and said second plane; wherein said resonant cavity has a center point, a first outer-most point and a second outer-most point defining the width of said resonant cavity; wherein the center point, the first outer-most point and the second outer-most point are collinear; wherein said input waveguide is offset from the first outer-most point of said resonant cavity and said output waveguide is offset from the second outer-most point of said resonant cavity; wherein the offset is described by the relationships: D oc >D iw ; and D ic >D ow ; wherein D oc is the distance between the center point of the cavity and the outer-most point of said resonant cavity, D iw is the distance between the center point of said resonant cavity and the inner-most point of the input waveguide, and D ow is the distance between the center point of the cavity and the outer-most point of said input waveguide; wherein the inner-most point of said input waveguide is the point on said input waveguide closest to the center point of said resonant cavity and the outer-most point of said input waveguide is the point on said input waveguide furthest from the center point of said resonant cavity and collinear with the center point of said resonant cavity and the inner-most point of said input waveguide.