FORMATION OF ENLARGED-DIAMETER TAPER HOLE IN AXIAL BORE OF CAPILLARY TUBE

摘要

A method is described of forming a tapered aperture at the end of a capillary tube bore (12). A gaseous etchant (22) such as a fluorine-containing compound flows through the bore (12) and emanates from the first end (14) of the tube (10). That tube end is heated to create a longitudinal temperature gradient. The gaseous etchant reacts with the tube (10) and enlarges that portion of the bore (12) at the first end. The resultant tapered aperture has a surface smoothness and shape that greatly facilitates the insertion of optical fibers during the fabrication of optical energy transfer devices.