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:
Jul. 29, 2003
Filed:
Dec. 04, 2000
Carl Gaebe, Ellicott City, MD (US);
Ciena Corporation, Linthicum, MD (US);
Abstract
An optical filter including a plurality of dielectric layers is provided between first and second substrates. The substrates have a coefficient of thermal expansion that is greater than that of the dielectric layers, and the thicknesses of the substrates are selected to provide compensation for temperature-dependant variations in the center wavelength of the filter. A variety of substrate materials may be used. Quartz is advantageous as a substrate material because it has relatively low loss at wavelengths commonly used in telecommunication systems. Moreover, it is thermally and chemically stable, and has good adhesion to most dielectric films used as quarter and half wave layers. Further, quartz is mechanically tough, relatively inexpensive and readily available. The quartz substrate is cut from a crystal and has an orientation with reduced birefringence.