Optical transmitting apparatus, optical receiving apparatus, and optical communication system comprising them
US8867927B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 10, 2010 |
| Grant date | Oct 21, 2014 |
| Priority date | — |
| Expiry date | Jul 5, 2032 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04B10/677
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
A phase shift unit provides a prescribed phase difference (π/2, for example) between a pair of optical signals transmitted via a pair of arms constituting a data modulation unit. A low-frequency signal f0 is superimposed on one of the optical signals. A signal of which phase is shifted by π/2 from the low-frequency signal f0 is superimposed on the other optical signal. A pair of the optical signals is coupled, and a part of which is converted into an electrical signal by a photodiode. 2f0 component contained in the electrical signal is extracted. Bias voltage provided to the phase shift unit is controlled by feedback control so that the 2f0 component becomes the minimum.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.