Polarization independent coherent optical heterodyne receivers
US4723316A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | May 8, 1986 |
| Grant date | Feb 2, 1988 |
| Priority date | — |
| Expiry date | May 8, 2006 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04B10/64
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
The present invention relates to coherent optical heterodyning receivers which mix a received optical signal, including an arbitrary polarization state, and a local oscillator signal, including a fixed polarization state, while providing a performance which is independent of the polarization direction of a received signal. In one receiver version, the received signal is heterodyned using only a portion of the local oscillator signal, while in a second receiver version, the entire local oscillator signal is used. The combined polarized signals are split in a polarizing beam splitter between the two orthogonal polarization axes for propagation in separate branches. Each branch includes a photodetector and means for processing the resulting photodetector output signal to retrieve the modulation information from the processed signal. The sum of the two demodulated signals from the two branches provides a baseband signal independent of the polarization state of the received optical signal.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.