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:
Sep. 26, 2006
Filed:
Jul. 05, 2002
Ulf Persson, Skogås, SE;
Ulf Persson, Skogås, SE;
Lumentis AB, Hagersten, SE;
Abstract
The present invention relates to a method using a node, a system comprising a node and a node for filtering signals in a wavelength division multiplexing (WDM) optical communications system, especially for re-configurably adding and dropping signals to and from an optical fibre path. The node comprising a drop filter, an add filter, a signal channel receiver, and a signal channel transmitter each being connected to a switch for signal channel relaying between said network, and signal channel dropping and adding from and to said network. The node provides low loss for relayed signals by allowing the drop filter to have a low crosstalk isolation, and provides high crosstalk isolation for dropped signal channels by connecting said receiver to the switch through an additional filter with high filtering characteristics for at least one predetermined signal channel of said signal.