Patent ID: 7218819
Filing Date: 2007-05-15
Classification: G02F

Abstract:
1. An electrode system for optical modulation for applying a voltage for modulating light propagating in an optical waveguide; said electrode system being provided on a substrate comprising one and other main faces opposing each other and made of an electrooptic material: said electrode system provided according to a coplanar-type electrode pattern, said electrode system comprising a ground electrode and a signal electrode, wherein a ratio “W/G” of a width “W” of said signal electrode to a gap “G” between said ground and signal electrodes is in a range of 2.5 to 5, said substrate has a thickness “T” of 20 μm or smaller in a region of said substrate where said optical waveguide is formed, said signal electrode has a thickness of less than 15 μm, and said substrate comprising an X-cut plate of a single crystal of lithium niobate; wherein: