| 摘要 |
PURPOSE:To obtain an optical control device which operates stably over a long period of time at a good yield. CONSTITUTION:This optical control device of a waveguide type consists of optical waveguides 2 formed on an LiNbO3 or LiTaO3 substrate 1 having an electro-optical effect, buffer layers 3 formed on these optical waveguides 2, electrodes 4a, 4b formed on the buffer layers 3 near the waveguides 2 and conductive films 6 formed on these electrodes 4a, 4b. An Li diffusion blocking layer 7 which blocks the diffusion of Li included in the substrate 1 into the buffer layers 3 is inserted between the buffer layers 3 and the substrate 1 and there are no buffer layers 3 in the region held by the electrodes 4a, 4b. Further, the device has a structure loaded with PSG films 8 on the buffer layers 3. |
