| 摘要 |
PURPOSE:To enable high concentration uniform doping of many elements, by forming a lithium niobate layer doped with rare earth elements having optical amplification action on a crystal substrate like lithium tantalate, and arranging an optical waveguide on the layer. CONSTITUTION:A lithium niobate crystal layer 12 is formed on a lithium tantalate crystal substrate or a lithium niobate crystal substrate 11 which layer is doped with rare earth element of erbium or neodymium or praseodymium and aluminum or germanium, and an optical waveguide 13 is arranged on the layer 12 by ion milling. Since lithium tantalate has the same crystal as lithium niobate, uniform epitaxial growth on the lithium tantalate crystal substrate 11 is enabled. The diffusion coefficient of element like erbium having optical amplification action is very small, and it is difficult to doped lithium niobate with erbium by thermal diffusion. Uniform doping, however, is enabled by adding raw material at the time of solvent fusing of liquid phase epitaxial. |
