| 摘要 |
PURPOSE:To manufacture a preform having uniform ratio of the core diameter to the outer diameter throughout the length, by controlling the transfer speed of the heating source moving along the length of a raw material glass tube in the production of an optical fiber preform by MCVD process. CONSTITUTION:A hollow glass tube 1 is manufactured by successively depositing the clad-forming glass component and the core-forming glass component to the inner wall of a glass tube. The tube 1 is heated with an oxyhydrogen burner 2 (movable heat source) moving toward the right-hand side of the figure, and the softened tube is collapsed to obtain an optical fiber preform. In the above process, the heating source 2 is moved slowly at the end part having low deposition of the core glass in the tube 1, and relatively rapidly at the other end having high glass deposition. |
