| 摘要 |
PURPOSE:Everytime the core glass layer is laminated with one layer, the moving speed of the burner is increased at a prescribed ratio to decrease the amount of piled layer at a certain ratio, whereby the thickness of each glass layer is made almost the same, when the fiber is made solid. CONSTITUTION:When optical fiber is formed by introducing argon gas and oxygen gas carrying e.g., silicon tetrachloride and germanium tretracloride into quartz pipe 21, allowing a heating burner 21 to move from one end D to the other end F to cause vapor phase reactions and pile up core glass layers in order unitl the quartz pipe 21 is fully filled and drawing the pipe under heating, the moving speed of the burner is increased at a prescribed ratio everytime one core glass layer is formed. Thus, a glass laminate of which each layer contains lesser amout than the former layer at a specific ratio is formed and made solid to become almost same thick in layers. Therefore, riple intervals between core glass layers become narrow to give fiber of focussing type in wide ranges. |
