| 摘要 |
PURPOSE:To obtain a groove whose dimension accuracy is high is obtained by a simple method by forming a groove for coupling on a photosensitive glass substrate by photoetching. CONSTITUTION:In the vicinity of the surface of a glass substrate 2 having optical penetrability of a branch coupler 1 for optical fiber, an optical path 3 is formed in accordance with an optical path to be allowed to branch, and in the end part of each optical path, grooves 4-6 for coupling optical fiber are formed by photoetching. In such a way, a large-scale device such as a press device for glass, etc., is not required, and also, the grooves 4-6 can be formed with high accuracy which etching working has. |
