| 摘要 |
PURPOSE:To maintain the high threshold value of an optical damage and to improve diffraction efficiency by forming an optical waveguide of a prescribed light function element without diffusing proton to the part to be provided with electrodes acting to the guided light thereby preventing the decrease in the piezo-electric characteristic and electrooptic characteristic of the crystal. CONSTITUTION:An optical function element has a proton diffused part formed by diffusing thermally a metal and proton to the surface of a lithium niobate crystal substrate or lithium tantalate crystal substrate and a proton undiffused part not diffused with the proton. An electrode part acting to the light guided in the surface of such substrate is provided in the proton undiffused part. The method for forming said part consists of a process for diffusing thermally the metal to the surface of the lithium niobate crystal substrate or lithium tantalate crystal substrate, a process for forming a mask to part thereon, a process for implanting the proton into the substrate in the part not covered with the mask and a process for diffusing thermally the proton and forming electrodes to the part covered by the mask, by which the manufacture of the optical function element is accomplished. |
