| 摘要 |
PURPOSE:To form a buffer layer with decreased DC drift in a simple production process. CONSTITUTION:A buffer layer 34 is formed on a ferroelectric crystal substrate 31 having an electro-optical effect in which an optical waveguide 33 is formed. The composition SiOx of the buffer layer 34 is controlled so that (x) is between >=1.6 and <2.0. Then control electrodes 35, 36 are formed on the buffer layer 34. By controlling the compsn. of the buffer layer 34 to the optimum, an optical waveguide element with decreased DC drift can be obtd. without adding any production process or a complicated process. |
