| 摘要 |
PURPOSE:To obtain the optical fiber preform of a low transmission loss by saving an atmosphere gas and suppressing the deformation of a muffle to prolong the life thereof, thereby enhancing economy and preventing the incorporation of impurities and the outdoor air. CONSTITUTION:The muffle 3 is so fixed to the circumference of soot 1 as to hermetically cover the circumference and a heater 4 placed around the soot fixed to the muffle is moved relatively to the soot and the muffle to heat the soot and the muffle, by which the dehydrating and sintering treatment of the soot in the muffle is executed. |
