Optical waveguide element and optical modulation device using same, and optical transmission device

Abstract

An object of the present invention is to provide an optical waveguide device that is capable of reducing a curvature radius of an optical waveguide and that suppresses coupling between a TE mode and a TM mode. In the present invention, an optical waveguide device includes a rib optical waveguide 10, in which a rib optical waveguide includes a straight linear part AR1 and a curved part AR3 configured to have a constant curvature, a curvature transition part AR2 in which a curvature continuously changes connects the straight linear part AR1 to the curved part AR3, a height and a width of the rib optical waveguide are different between the straight linear part and the curved part, and the curvature transition part AR2 is formed such that the height and width of the rib optical waveguide continuously change from a height and a width of the straight linear part to a height and a width of the curved part, respectively.

Dependencies are inferred from the claim text.