Patent ID: 7400786
Filing Date: 2008-07-15
Classification: G02F

Abstract:
1. An optical modulator comprising a substrate having an electro-optic effect, an optical waveguide formed on the substrate, a signal electrode formed on the substrate, and a ground electrode formed on the substrate at a position spaced apart from the signal electrode, and having a configuration in which, in an interaction section where light propagated through the optical waveguide, and an electrical signal propagated through the signal electrode interact with each other, a first region positioned on an input side in a light propagation direction, and a second region positioned on an output side are set, and a direction of a change in an optical phase determined depending on a relationship between a polarizing direction of the substrate and a direction of an electric field interacting with the light in each of the first and second regions is reversed, wherein the first and second regions are configured in a manner such that an electrical loss per unit length produced over an entire region of the second region is relatively higher in its value than the electrical loss per unit length produced in the first region, with respect to a frequency signal component that is contained in the electrical signal propagated through the signal electrode and corresponds to optical modulating speed.