Method and apparatus for improving spectral efficiency in wavelength division multiplexed transmission systems
US6134033A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 26, 1998 |
| Grant date | Oct 17, 2000 |
| Priority date | — |
| Expiry date | Feb 26, 2018 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04J14/06
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
A method and apparatus is provided for transmitting an optical signal. The method includes the step of generating an optical signal that includes a plurality of optical channels, which are sequentially numbered from 1 to N from lowest to highest wavelength. A state-of-polarization of predetermined odd-numbered channels is oriented to be substantially orthogonal to a state of polarization of predetermined even-numbered channels by directing the predetermined odd-numbered channels and the predetermined even-numbered channels through orthogonally polarizing inputs of a polarization coupler. The odd-numbered channels and the even-numbered channels may be directed through first and second wavelength combiners, respectively, prior to orienting their states of polarization. The orthogonal relationship between the states of polarization of odd and even-numbered channels advantageously limits the four-wave mixing products that can be generated in the optical transmitter and the optical transmission path to which it is typically coupled.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.