Apparatus and method for monitoring optical signal-to-noise ratio
US7391970B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 30, 2004 |
| Grant date | Jun 24, 2008 |
| Priority date | — |
| Expiry date | Feb 11, 2027 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04B10/07957
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
An apparatus and a method for monitoring optical signal-to-noise ratio are provided. It can be applied in dense wavelength-division multiplexed networks to monitor the transmission quality of each optical channel. The apparatus comprises an optical circulator, a tunable optical filter, a dithering signal, a dithered reflector, and two photodiodes. It can be integrated on a single chip. The invention utilizes the dithering and reflection functions of the dithered reflector, and passes the signal and the noise through the tunable optical filter once and twice, respectively. When the tunable optical filter is scanning and filtering the whole spectrum, the signal and noise powers are measured by the two photodiodes, respectively. The OSNR for each optical channel is then calculated according to the signal and noise powers. It can monitor channel location, wavelength drift, and OSNR by including a wavelength locker to act as an optical channel analyzer.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.