| 摘要 |
PROBLEM TO BE SOLVED: To provide an optical modulator which works at a high speed, has a small alpha parameter and a large extinction ratio, and also has a small driving voltage and DC bias voltage. SOLUTION: The optical modulator has a Mach-Zehnder optical waveguide equipped with a substrate 1 having electrooptic effect, an optical waveguide 12 formed on the substrate 1 and guiding light, and a progressive-wave electrode 4 comprising a center conductor 4a for a high-frequency electric signal formed on one surface side of the substrate 1 and applying the high-frequency electric signal for modulating light and ground conductors 4b and 4c, and the optical waveguide 12 has a plurality of optical waveguides 12a and 12b for interaction which modulate the phase of the light by applying the high-frequency electric signal to the progressive-wave electrode 4. The plurality of optical waveguides 12a and 12b for interaction have at least one or more high-refractive-index areas 13a and 13b, where the plurality of optical waveguides 12a and 12b for interaction are different in refractive index from each other in a section perpendicular to the length of the optical waveguide 12, partially along the lengths. COPYRIGHT: (C)2007,JPO&INPIT |
