LIGHT MODULATOR OF WAVEGUIDE TYPE

摘要

An optical waveguide modulator 40 according to the present invention has a substrate 1 made of a material with an electrooptic effect, an optical waveguide 2 to guide a lightwave 2, a travelling wave-type signal electrode 3 and the ground electrodes 4 to control the lightwave. Moreover, it has a buffer layer 6, at least a part thereof being embedded in the superficial layer of the substrate 1, having a larger width "W" than a width " omega " of the travelling wave-type signal electrode 3 only under the signal electrode 3 and its nearby part. <IMAGE>