Carrier-suppressed optical time domain multiplexing
US7574139B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | May 31, 2002 |
| Grant date | Aug 11, 2009 |
| Priority date | — |
| Expiry date | Jan 17, 2026 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04J14/08
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
A method and an apparatus for implementing carrier suppressed data format on conventional OTDM modules is provided. Adaptive phase shifting of optical signals traversing one of the tributaries of an OTDM module is performed with feedback loop control. A tapped portion of the input carrier signal is phase modulated at a frequency fc, and is combined with a tapped portion of the output from the OTDM. A phase shifter controller fed with this combined signal photodetects and band-pass filters the signal around fc to extract the amplitude of the AC component of the envelope of the combined signal, which depends upon the phase difference between successive pulses of the OTDM output. This signal is used to control a phase shifter coupled along one of the tributaries of the OTDM to adjust the phase difference of the signals of the two tributaries so that carrier suppression results.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.