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:
May. 18, 1999
Filed:
Apr. 23, 1997
Applicant:
Inventors:
Sureshchandra Mishrilal Ojha, Harlow, GB;
Jonathan Paul Stagg, Sawbridgeworth, GB;
Assignee:
Northern Telecom Limited, Quebec, CA;
Primary Examiner:
Int. Cl.
CPC ...
H01L / ;
U.S. Cl.
CPC ...
438 31 ; 385131 ; 385132 ; 385144 ;
Abstract
A cladding layer on the core of an optical waveguide is subjected to a rapid thermal annealing process preferably either: in a multi-stage furnace in which the waveguide substrate can be transported rapidly on a carriage between stages at different temperatures; or in a quartz chamber adjacent a bank of quartz halogen lamps of low thermal inertia and easily switched rapidly between different intensities of thermal radiation through the chamber.