ION EXCHANGE TYPE X-BRANCHED OPTICAL WAVEGUIDE DEVICE

PROBLEM TO BE SOLVED: To improve wavelength properties in the long wavelength side from 1.48-1.58 μm. SOLUTION: An optical waveguide device has an asymmetric X-branched structure formed by combining an asymmetric waveguide branch 10 composed of two optical waveguides having propagation constants different from each other and a symmetric waveguide branch 12 composed of two optical waveguides having propagation constants identical to each other. Also the optical waveguide device satisfies a condition of Δβ/(θ×γ)>0.43 (wherein Δβ is a propagation constant difference, θ is a crossing branch angle, and γ is an attenuation constant of radiation light of a branched part). Each of the optical waveguides is an ion exchange type optical waveguide formed on a glass substrate 14 by ion exchange. A refractive index difference between the optical waveguide having a smaller propagation constant of the asymmetric waveguide branch and the glass substrate is set larger than 0.0074. COPYRIGHT: (C)2009,JPO&INPIT