METHOD FOR MANUFACTURING OPTICAL FIBER

摘要

This invention provides a method for manufacturing an air cladding-type optical fiber by a method other than extrusion molding. In the method, an optical fiber comprising a hollow glass fiber and an optical transmission glass extended axially in the center of the hollow glass fiber. A glass rod is provided in which three or more holes with an identical diameter provided around the central axis and extended in the axial direction are provided so that the distance between the axis of each hole and the central axis is identical, the distance between the axes of the holes is identical, and a part surrounded by these holes is the optical transmission glass part. One end of the glass rod is sealed, and, while applying pressure to the holes, the rod is heated to expand the holes and is drawn to prepare a preform in which the glass between the holes is in a plate form. The preform is wiredrawn to prepare an optical fiber comprising the optical transmission glass held by the plate glass.