Filter topologies for optical add-drop multiplexers
US6188816A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Sep 8, 1999 |
| Grant date | Feb 13, 2001 |
| Priority date | — |
| Expiry date | Sep 8, 2019 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04J14/0209
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
A filter topography is possible that can reduce the overall cost of a single Optical Add-Drop Multiplexer (OADM) or a series of OADMs that are within a network. The key is to have one of the wavelengths of a WDM signal being input to a filtering apparatus empty. The filtering apparatus can then with a reduced cost filter the received WDM signal such that a channel at a wavelength adjacent to the empty wavelength is removed and a channel is inserted at the previously empty wavelength. In one implementation of this topology within an OADM, a single filter can be used to perform both filtering operations due to the empty wavelength ensuring no corruption of the removed channel at the adjacent wavelength. In another implementation, the filtering operations are performed by two separate filters that each have asymmetrically reduced tolerances. In either case in which there is a reduced number of filters or reduced tolerances for those filters, a reduction in cost will be found.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.