| 摘要 |
PURPOSE:To provide the subject equipment for producing a preform of an optical fiber. In this equipment, the variation of the refractive index is minimized in the longitudinal direction of the preform by stabilizing the gas current in the neighborhood of the upper part of the porous preform when depositing fine glass particles injected through burners and growing the porous preform according to VAD method, etc. CONSTITUTION:In related to a production equipment for depositing fine glass particles injected through burners 3a to 3c on a rotary seed rod 1 in a chamber 2 and growing a porous preform (M), the subject equipment for producing a preform of an optical fiber is equipped with a cylindrical auxiliary chamber 6 surrounding at least the neighborhood of the upper part of the above-mentioned porous preform (M) leaving some space and designed so that the gas current may stably flow downward from the upper part of the above-mentioned porous parent material (M) in the neighborhood of the upper part of the preform (M) by a function of the above-mentioned cylindrical chamber 6. Owing to stabilization of the gas current, a preform of an optical fiber reduced in the variation of the refractive index in the longitudinal direction of the preform to a minimum can be produced. |
