Patent ID: 7330613

Claim:
A waveguide type optical device comprising: a substrate having an electro-optic effect and opposed end faces at ends of the substrate in a longitudinal direction and opposed side faces; an optical waveguide which is formed on the substrate and which includes: a plurality of functional optical waveguides, wherein light guided through the functional optical waveguides interacts with an applied electric signal; an optical input end face and an optical output end face which are provided at respective ones of the end faces of the substrate; and an input optical waveguide connecting the optical input end face and the functional optical waveguides, and an output optical waveguide connecting the optical output end face and the functional optical waveguides; and at least one of a signal light monomode optical fiber which has an end located opposite to the input optical waveguide at the optical input end face and which inputs light to the input optical waveguide, and a signal light monomode optical fiber which has an end located opposite to the output optical waveguide at the optical output end face and which receives light output from the output optical waveguide, wherein at least one of the input optical waveguide and the output optical waveguide is arranged to form an angle other than 0° with the functional optical waveguide connected thereto such that the at least one of the input optical waveguide and output optical waveguide is not coincident with the functional optical waveguide connected thereto, and wherein the at least one of the input optical waveguide and the output optical waveguide is arranged such that the at least one of the input optical waveguide and the output optical waveguide is not perpendicular to the corresponding one of the substrate end faces, and wherein the at least one of the input optical waveguide and the output optical waveguide is arranged such that the light input to or output from the at least one signal light monomode optical fiber is inclined at a desired angle with respect to the corresponding side face of the substrate.