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:
Apr. 24, 2001
Filed:
Apr. 08, 1999
Patrick William Wisk, Greenbrook, NJ (US);
James Dennis Wynn, Plainfield, NJ (US);
Man Fei Yan, Berkeley Heights, NJ (US);
Lucent Technologies Inc., Murray Hill, NJ (US);
Abstract
The specification describes a process and apparatus for collapsing preform tubes in Modified Chemical Vapor Deposition processes. The problem of bubble formation during tube collapse was found to be attributable to excess dopant vapor pressure emitted from the hot zone during the final stage of tube collapse. This excess pressure is controlled by cooling the tube in advance of the torch, thereby decreasing the viscosity of the dopant vapor and increasing its transport rate. This is found to reduce internal tube pressure and eliminate bubble formation in the collapsed preform.