LAMINATED INTERLAYER OPTICAL DIRECTIONAL COUPLER AND ITS MANUFACTURING METHOD

摘要

PROBLEM TO BE SOLVED: To provide an optical directional coupler between laminated waveguides and its manufacturing method with respect to a laminated optical waveguide realizing high density integration. SOLUTION: In the laminated directional coupler wherein clad layers 313, 314 and 315, and cores 302 and 303 are formed by being repeated a plurality of times on one surface of a substrate 312 to form optical waveguides consisting of n layers in a laminated shape and also optical coupling is performed between respective optical waveguides, the cores 302 and 303 are arranged closely to each other in the direction orthogonal to the substrate only in optical coupling areas 316 and 317 via the optical waveguide which is smoothly curved in the direction orthogonal to the substrate. The cores 302 and 303 are satisfactorily separated in an area other than the coupling area.