Abstract: An optical modulator includes an optical waveguide formed on a substrate and modulates a light wave propagating through the optical waveguide, in which the optical waveguide has a configuration in which a plurality of branching parts are connected to each other in multiple stages, each of branched waveguides branched from a branch point of a first branching part among the plurality of branching parts has a transition curve of which a curvature changes, in a predetermined section from the branch point, each of the branched waveguides is formed by the transition curve starting from a curvature of 0, and a curvature change and a width change of the optical waveguide are set to be symmetric between the branched waveguides, and second branching parts formed in the respective branched waveguides are disposed at different positions between the branched waveguides in a direction along a propagation axis of the optical waveguide.

Abstract: Provided is an optical element module including: a substrate; an optical modulator unit that is formed in the substrate and includes an optical waveguide; a first lens unit that is disposed on an end surface of the substrate, and includes a lens portion at which a signal light beam emitted from the optical modulator unit is collimated; and a second lens unit that introduces the signal light beam passing through the first lens unit to an optical fiber.

Abstract: An optical modulator includes an optical waveguide formed on a substrate and modulates a light wave propagating through the optical waveguide, in which the optical waveguide has a configuration in which a plurality of branching parts are connected to each other in multiple stages, each of branched waveguides branched from a branch point of a first branching part among the plurality of branching parts has a transition curve of which a curvature changes, in a predetermined section from the branch point, each of the branched waveguides is formed by the transition curve starting from a curvature of 0, and a curvature change and a width change of the optical waveguide are set to be symmetric between the branched waveguides, and second branching parts formed in the respective branched waveguides are disposed at different positions between the branched waveguides in a direction along a propagation axis of the optical waveguide.

Abstract: An optical waveguide device includes a substrate in which an optical waveguide is formed. The optical waveguide has a Y-branched structure in which light beams propagating through a main waveguide are branched into two parts, and a three-branched structure in which the optical waveguide is branched into three waveguides including the main waveguide and two sub-waveguides on both sides of the main waveguide at a front stage of the Y-branched structure. The main waveguide includes a linear waveguide portion in which a waveguide width is constant and a tapered waveguide portion in which the waveguide width gradually increases between the three-branched structure and the Y-branched structure.

Abstract: An optical waveguide device includes a substrate in which an optical waveguide is formed. The optical waveguide has a Y-branched structure in which light beams propagating through a main waveguide are branched into two parts, and a three-branched structure in which the optical waveguide is branched into three waveguides including the main waveguide and two sub-waveguides on both sides of the main waveguide at a front stage of the Y-branched structure. The main waveguide includes a linear waveguide portion in which a waveguide width is constant and a tapered waveguide portion in which the waveguide width gradually increases between the three-branched structure and the Y-branched structure.

Abstract: Provided is an optical element module including: a substrate; an optical modulator unit that is formed in the substrate and includes an optical waveguide; a first lens unit that is disposed on an end surface of the substrate, and includes a lens portion at which a signal light beam emitted from the optical modulator unit is collimated; and a second lens unit that introduces the signal light beam passing through the first lens unit to an optical fiber.