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:
Nov. 26, 2002
Filed:
Jun. 07, 1999
Douglas M. Baney, Palo Alto, CA (US);
Norihide Yamada, Tokyo, JP;
Satoshi Watanabe, Yokohama, JP;
Shigeru Nakagawa, Goleta, CA (US);
Yoshikatsu Ichimura, Tokyo, JP;
Agilent Technologies, Inc., Palo Alto, CA (US);
Abstract
A method and a system for monitoring specific channels in a WDM system involve splitting a WDM signal into multiple parallel signals, filtering the parallel signals with corresponding individually tunable filters in order to pass specific channels to each filter, and then detecting the presence of passed channels with dedicated detectors that correspond to the tunable filters. In a preferred embodiment, the initial WDM signal is demultiplexed by wavelength into multiple different transmission groups and each filter can be individually tuned over a channel range that corresponds to the range of channels within the transmission group that is directed to the filter. The preferred individually tunable filters are vertical cavity filters formed utilizing semiconductor wafer processing techniques, and the preferred photodetectors are simple low cost single-cell photodetectors.