| 摘要 |
PURPOSE:To provide a structure of an optical waveguide having optical amplification function or the like which can be easily produced, and to provide the production method. CONSTITUTION:An impurity-doped layer 8b obtd. by doping with rare earth elements by sol-gel method is formed between the first and second core layers 8a, 8c by sputtering or flame deposition method so that the core part 8d formed on the substrate 4 has a three-layer laminated structure. This structure is produced by the following process. In the first process, the first core layer 8a to constitute the core part 8d is formed on the substrate 4 and the core layer 8a is doped with rare earth elements by sol-gel method to form an impurity- doped layer 8b on the core layer 8a. Then, the second core layer 8c is formed thereon. In the second process, each layer 8 on the substrate 4 is etched to form the core part 8d. In the third process, a clad part 9 is formed on the substrate 4 where the core part 8d of a three-layer structure is formed. |
