Selective intensity modulation of channels in a multiplexed optical communication system
US6529307B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 4, 2001 |
| Grant date | Mar 4, 2003 |
| Priority date | — |
| Expiry date | Jun 4, 2021 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04B10/532
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
A method and apparatus for achieving dynamic intensity modulation of the channels in a wavelength-division multiplexed optical communication system is presented. Wavelengths are spatially separated into a plurality of channels, the polarization states of which are individually modulated. The channels can be combined or filtered by polarization states to achieve the desired intensity in the output signal. An exemplary embodiment includes at least a polarization modulator, a birefringent wedge, a lens, and a dispersive element (e.g., diffraction grating) arranged in various order. Each segment of the polarization modulator can be made to rotate the polarization direction of an incident channel by a specified angle. A half-wave plate may be inserted between the second dispersive element and the second birefringent wedge to eliminate polarization-dependent loss. Optionally, a parallel birefringent plate may be inserted after the second birefringent wedge to reduce polarization mode dispersion.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.