Waveguide type optical control device with properties of suppressed DC drift, reduced driving voltage and high speed operation

摘要

An optical control device has two waveguides 2a, 2b close to each other formed in a main surface of a substrate 1 of a dielectric and light-transparent material with an electrooptic effect. A buffer layer is formed on the main surface in three spaced sections 3a, 3b, and three electrodes 4a, 4b, 4c are formed on respective sections of the buffer layer, so that the electrodes are respectively positioned between and outside the waveguides 2a, 2b. Each of the two outside electrodes 4b, 4c extends along a side surface of the respective outside buffer layer section 3b so as to contact directly the main surface. Alternatively, each outside electrode 4b, 4c can extend through a hole formed in the respective outside buffer layer 3b section, or the outside buffer layers 3b can be omitted so that the outside electrodes 4b, 4c are entirely in contact with the main surface.