| 摘要 |
PURPOSE:A hollow tube of SiO2 fine grains is heated inside to sinter its inner wall, then heated in an atmosphere containing fluorine to effect glassification whereby single-mode optical fiber of low transmission loss is obtained. CONSTITUTION:A heater 7 is set inside the soot pipe (a hollow tube of SiO2 fine particles) 4 (6 is a protecting pipe, 5 is a spacer). The soot pipe 4 is put in the muffle furnace 8 (9 is a working coil for high-frequency heating) and the inner wall and its nearby parts are sintered with the inserted heater 7. Then, the resulting soot pipe 4 is melted for clarification in an atmosphere containing gaseous fluorine compounds to give the objective parent material for optical fibers. |
