| 摘要 |
<p>Disclosed are an optical fiber preform manufacturing apparatus and method in which processes for shrinking and closing a deposited tube are conducted using a device suitable for those processes, which device is other than the device used in a deposition process for forming the deposited tube on the inner surface of a preform tube, thereby reducing the processing time while reducing the amount of OH penetrated from the preform tube into a vitreous component of the deposited tube, thereby achieving a reduction in OH loss. In accordance with the optical fiber preform manufacturing apparatus and method, operations are conducted which involve setting the heating temperature of a circular heater to a temperature lower than the softening point of a deposited tube, exhausting contaminants existing in the interior of the deposited tube while moving the circular heater at a desired temperature, setting the heating temperature of the circular heater to a temperature not lower than the softening point of the deposited tube, and shrinking and closing the deposited tube while moving the circular heater to a desired temperature.</p> |
