Patent ID: 6798952
Filing Date: 2004-09-28
Classification: G02B

Abstract:
An optical multiplexer/demultiplexer having a waveguide structure, the structure comprising:one or more optical input waveguides arranged; a first sector slab waveguide located on the output side of the optical input waveguides; an arrayed waveguide including a plurality of waveguides arranged any adjacent two of which differ in length by a constant value for propagating light output from the first sector slab waveguide; a second sector slab waveguide connected to the output side of the arrayed waveguide; and a plurality of optical output waveguides arranged and connected to the output side of the second sector slab waveguide, wherein the optical input waveguides and the first sector slab waveguide are connected by a directional coupler having a symmetrical structure, the coupler comprising: a central waveguide including an end portion on the first sector slab waveguide side of the optical input waveguides on both side portions of which a taper is formed so that the width of a core will gradually narrow in the direction of the end portion, and not touching the first sector slab waveguide; and a plurality of arranged waveguides one end of each of which is connected to the input side of the first sector slab waveguide and which are arranged on both sides of the central waveguide by the same numbers.