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:
Aug. 27, 2002
Filed:
Jul. 09, 1999
Giovanni Barbarossa, Tucker, GA (US);
Chellappan Narayanan, Alpharetta, GA (US);
Agere Systems Guardian Corp., Orlando, FL (US);
Abstract
Transmission characteristics of an optical device , fabricated from multiple layers of silica-based glass on a silicon substrate , are modified by localized thermal treatment. The beam of a carbon-dioxide (CO ) laser is used to selectively soften the core and/or cladding material of a waveguide structure during or after the fabrication process. In one application, softening relieves the strain developed between the waveguide structure and the silicon substrate and substantially reduces or eliminates birefringence. In a second application, the CO laser is operated at another power level in order to modify the index of refraction. Changes in the index of refraction change the speed of light through a waveguide thereby changing the phase shift associated with the waveguide. In a third application, the CO laser is operated at yet another power level to increase the transmission loss of the waveguide. In all of the embodiments, heat treatment is substantially faster and/or less expensive than known techniques for modifying the transmission characteristics of an optical device.