Patent ID: 9551887
Date: 2017-01-24
CPC Classifications: G02F

Claim:
1. An optical modulator comprising: a base body section having a principal surface; a ridge optical waveguide provided on the principal surface of the base body section and extending along a first direction along the principal surface; and a modulation electrode for modulating light guided through the ridge optical waveguide, wherein the principal surface of the base body section has an installation surface on which the ridge optical waveguide is provided, and first and second surfaces which are located so as to interpose the installation surface therebetween along a second direction orthogonal to the first direction and along the principal surface, wherein the modulation electrode is composed of a signal electrode to which a modulation signal is supplied, a first ground electrode, and a second ground electrode, wherein the signal electrode has a wide portion being a portion provided on the ridge optical waveguide so as to extend along the first direction, the wide portion having a width in the second direction wider than a width in the second direction of an uppermost portion of the ridge optical waveguide, wherein the first ground electrode has a first ground electrode component provided on the first surface so as to extend along the first direction, wherein the second ground electrode has a second ground electrode component provided on the second surface so as to extend along the first direction, wherein the first ground electrode component has at least one first through-hole provided in only a portion in the first direction of the first ground electrode component, wherein the second ground electrode component has at least one second through-hole provided in only a portion in the first direction of the second ground electrode component, wherein the at least one first through-hole overlaps the wide portion of the signal electrode or faces the wide portion in the second direction as seen in a planar view, and wherein the at least one second through-hole overlaps the wide portion of the signal electrode or faces the wide portion in the second direction as seen in a planar view.