| 摘要 |
PROBLEM TO BE SOLVED: To provide an optical modulator which can be driven at a high speed with a low voltage and can suppress DC drift, having high reliability and a good yield of manufacturing. SOLUTION: The optical modulator is provided with: a substrate 1 having an electro-optical effect and including at least a face azimuth of x-cut or y-cut; an optical waveguide 3 for wave-guiding the light formed in the substrate; an electrode 4 consisting of a central conductor 4a and grounding conductors 4b, 4c formed on one face side of the substrate for applying voltage to modulate the light; and interactive parts 3a, 3b for the optical waveguide 3 to modulate the phase of the light by applying voltage across the central conductor 4a and the grounding conductors 4b, 4c. The optical modulator is also provided with: a conductive layer 15 which is electrically in contact with a part of the substrate upper surface and is formed so as not to cover the upper surface of the optical waveguide 3; a second buffer layer 16 formed above the conductive layer 15; and the central conductor 4a formed on the second buffer layer 16 in npn-contact with the conductive layer 15 in the interactive parts 3a, 3b. COPYRIGHT: (C)2007,JPO&INPIT |
