Hollow tube method for forming an optical fiber

Abstract

A method for forming an optical fiber from a single characteristic glass includes arraying hollow starter tubes about a central axis with each starter tube contacting its adjoining tubes along respective lines of contact to define a longitudinally extending opening about the central axis. The arrayed starter tubes are heated to cause them to fuse together along their lines of contact, and the fused starter tubes are inserted into a jacketing tube, preferably having the same physical and optical properties as the starter tubes. A pressure differential is established between the interior of the starter tubes and the tube-defined longitudinally extending opening. The tube assembly is heated to allow the established pressure differential to cause portions of the starter tubes to reform by moving toward and to the central axis to create a solid, void-free core and supporting webs. Other portions of the starter tubes expand toward and fuse to the interior surface of the jacketing tube. The resulting optical fiber has a central core supported from the interior of jacketing tube by the starter tube-defined webs with all the structural features of the fiber formed from a glass having the same physical and optical properties.

Dependencies are inferred from the claim text.