Patent ID: 7031569
Filing Date: 2006-04-18
Classification: G02B

Abstract:
1. An optical multi-demultiplexer comprising: a substrate; input waveguides formed on the substrate; a channel waveguide array including a plurality of curved waveguides arranged such that optical path lengths of adjacent ones of the curved waveguides are gradually increased from an inside toward an outside of a curved configuration of the curved waveguides; output waveguides formed on the substrate; a first slab waveguide formed between the input waveguides and the channel waveguide array; a second slab waveguide formed between the channel waveguide array and the output waveguides, and a different refractive index region formed at a position close to the channel waveguide array within the second slab waveguide, the different refractive index region having a lower refractive index than a core of the second slab waveguide, the different refractive index region extending in a direction in which the waveguides of the channel waveguide array are arranged, and the different refractive index region having a tapered shape decreasing in width from both side portions toward a central portion of the second slab waveguide.