OPTICAL FILTER AND MANUFACTURING METHOD OF THE SAME

摘要

A wavelength multiplexing/demultiplexing optical filter module and a manufacturing method of the same are provided to remove effectively optical coupling loss without forming an additional waveguide. An input-side star coupler of a slap waveguide type is connected to an input waveguide. An arrayed waveguide includes a plurality of individual waveguides having heterogeneous waveguide sections. In the heterogeneous waveguide sections, refractive indexes of waveguide cores are different from each other. The heterogeneous waveguide sections have a length difference therebetween. An output-side star coupler of a slap waveguide type is connected to the arrayed waveguide. One or more output waveguides are connected to the output-side star coupler. The heterogeneous waveguide sections includes a clad of a core(404) having a small refractive index and a clad of a core(403) having a large refractive index.