Single channel four-port group delay compensation equalizer
US7457544B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 16, 2004 |
| Grant date | Nov 25, 2008 |
| Priority date | — |
| Expiry date | May 26, 2026 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04J14/02
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A group delay compensation equalizer is disclosed that employs a single channel four-port WDM device for compensating the group delay experienced by a plurality of wavelengths transmitted over different paths. The transmission differential between two wavelengths is compensated by transmitting the two wavelengths through two different paths where the fiber length in reflecting the second wavelength is equal to the transmission time difference between the two wavelengths. The single channel four-port group delay equalizer effectively provides a unidirectional signal flow, as compared to the conventional equalizer that transmits optical signals bi-directionally. The present invention reduces the cost of a group delay equalizer by simplifying the use of multiple three-port WDM devices into a single channel four-port WDM device. The present invention further reduces the number of alignments required to just one on the transmission side since the group delay equalizer now has one transmission output, rather than two transmission outputs in a prior solution.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.