METHOD OF PRODUCING OPTICAL FIBRES

摘要

A method is provided of producing optical fibres having improved core roundness and core-clad axis concentricity. Prior to the step of forming a layer of core material (48) on the inner surface of a bait tube (8), the tube is pressurized and heated and shrunk at least 1 mm and thereafter the pressure is increased to inflate the tube (8) until the outside diameter thereof approximates that of the originally provided bait tube.