Optical filtering by using an add-drop node
US7113662B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Jul 5, 2002 |
| Grant date | Sep 26, 2006 |
| Priority date | — |
| Expiry date | Jul 5, 2022 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04J14/0227
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
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.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.