The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Oct. 17, 2000
Filed:
Mar. 22, 1999
Jean-Claude Rousseau, Chatou, FR;
Raphaelle Sauvageon, Thones, FR;
Alcatel, Paris, FR;
Abstract
In a method of shrinking a tubular optical fiber preform with a doped silica core the preform is placed on a glassmaking lathe to rotate it about an axis, a torch is moved parallel to the axis in front of the preform to shrink it and collapse it in a number of passes, and during an etching pass a mixture of oxygen and a fluorine precursor gas is injected through one end of the incompletely collapsed preform to eliminate a certain layer from the core. During the etching pass, a certain value of the pressure of the gaseous mixture at the end of the preform is determined and the speed of the torch is slaved to this pressure value. Controlling the speed of the torch stabilizes the pressure of the gaseous mixture inside the preform, which longitudinally homogenizes the diameter of the core and the refractive index difference relative to an optical cladding around the core.