| 摘要 |
PURPOSE:To manufacture the titled base material reducing the absorption loss of ultraviolet light by depositing a glass layer contg. Ge oxide on the inner wall of a hollow reaction tube, forming a surface glass film on the glass layer, and making the reaction tube solid. CONSTITUTION:A hollow reaction tube 1 attached to the rotating support mechanism of a glass lathe is rotated in the direction of an arrow 4, and gaseous starting materials for forming a glass layer contg. Ge oxide are introduced into the tube 1 from the direction of an arrow 3. While moving a heating source 2 in the longitudinal direction of the tube 1, the tube 1 is locally heated to deposit a glass layer 5 for the core part of an optical transmission line on the inner wall of the tube 1. A gaseous starting material for forming a glass layer contg. no Ge oxide is then introduced into the tube 1, and a surface glass film 21 contg. no Ge oxide is formed on the glass layer 5. The tube 1 is heated to a high temp. with the heating source 2, and it is made solid by carrying out melt bonding so as to provide a dense cross-section. |
