METHOD OF MAKING OPTICAL FIBERS HAVING IMPROVED CORE ROUNDNESS

摘要

A method of producing optical fibers having improved core roundness and core-clad axis concentricity. Prior to the step of forming a layer of core material on the inner surface of a bait tube, the tube is pressurized and heated and shrunk at least 1 mm and thereafter the pressure is increased to inflate the tube until the outside diameter thereof approximates that of the originally provided bait tube.