Patent attributes
The present invention relates to a composite optical waveguide (1) containing a polymer optical waveguide and a silicon optical waveguide adiabatically coupled to each other, in which the polymer optical waveguide and the silicon optical waveguide are coupled to each other by an adhesive layer in an adiabatic-coupling portion where a core of the polymer optical waveguide and a core of the silicon optical waveguide are disposed to face each other, the adhesive layer is formed by using a photocurable adhesive having a glass transition point Tg being 125° C. or higher after curing, and the adiabatic-coupling portion includes a region in which a spacing t between the core of the polymer optical waveguide and the silicon optical waveguide is 1.5 μm or less.
