METHOD OF ENLARGING END OF CAPILLARY TUBE BORE

摘要

A method of forming a tapered aperture at the end of a capillary tube bore. A gaseous etchant such as a fluorine-containing compound flows through the bore and emanates from the first end of the tube. That tube end is heated to create a longitudinal temperature gradient. The gaseous etchant reacts with the tube and enlarges that portion of the bore 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.