Optical transmitting apparatus and optical communication system
US7848659B2 · kind B2 · utility
12Cited by
26References
19Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Dec 12, 2005 |
| Grant date | Dec 7, 2010 |
| Priority date | — |
| Expiry date | Jan 23, 2027 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04B10/58
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
A data modulator unit generates a DQPSK optical signal in accordance with a data signal. A phase shift unit provides a phase difference of π/2 between a pair of arms. A photodetector converts an output signal of the data modulator unit into an electrical signal. A filter is a low-pass filter with a cut-off frequency lower than a symbol frequency, and filters an output signal of the photodetector. A monitor unit detects power of an output signal of the filter. A phase difference control unit adjusts the amount of phase shift in the phase shift unit so as to minimize power of an output signal of the filter.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.