| 摘要 |
PURPOSE:To facilitate manufacture and obtain the low operation voltage and high speed operation by making the thickness of a buffer layer under one electrode, larger at the part separated from a light wave guide part in comparison with the part close to the optical waveguide. CONSTITUTION:The wave guide type light control device is equipped with the optical waveguides 3 - 5 formed on a crystal substrate 1 which possesses the photoelectric effect, buffer layer 16 formed on the optical waveguides 3 - 6, and at least a pair of electrodes 7 and 8 a part of which is installed on the buffer layer 16. The phase speed of the microwave is increased by increasing the thickness of the buffer layer 16 under the electrodes 7 and 8 at the part separated from the optical waveguides 3 - 5, and the phase speed of the microwave is made close to that of the light wave. At this time, the buffer layer 16 is kept thin at the part close to the optical waveguides 3 - 5, i.e., at the part generating an electric field in the optical waveguide. Accordingly, the increase of the operation voltage is small, and the phase speed matching of the microwave and light wave and the low voltage operation can be satisfied at the same time. |
