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. 29, 2003
Filed:
Nov. 24, 1998
Evan Lee Goldstein, Princeton, NJ (US);
Lih-Yuan Lin, Middletown, NJ (US);
Leda Maria Lunardi, Marlboro, NJ (US);
AT&T Corp., New York, NY (US);
Abstract
The present invention provides a variety of methods and apparatus for monitoring signal quality and switch operation for optical switches in an optical cross connect. The signal quality can be checked by using a beamsplitter to reflect a portion of the light beam carrying the signal onto a photodetector which is connected to a device which can monitor loss of signal, loss of frame, and other transmission characteristics. The position of a switch or waveguide can be monitored by circuits which detect variable levels of resistance and capacitance based on the switch's position or by reflecting probe light beams off the back of the switching mirror. The present invention also provides a method for determining if the signal quality photodetector is functioning correctly.