High resolution optical performance monitor for DWDM system
US6396051B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 7, 2000 |
| Grant date | May 28, 2002 |
| Priority date | — |
| Expiry date | Jun 7, 2020 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04B10/07953
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
An apparatus for measuring the optical-signal-to-noise ratio (OSNR) of an optical system is adapted to function in single channel or in multi-channel wavelength division multiplexed optical communication systems. An optical signal spectrum and a center frequency characterize the optical signals. A narrow-band notch filter, realized by an in-fiber Bragg grating, is utilized to remove a component of the signal so the remaining signal can be measured. When multiple channels are present, a bandpass filter is used to select the part of the multiplexed signal to be measured. Both the narrow-band notch filter and the bandpass filter can be tunable to further extend the capabilities of the system. Two detectors are utilized with the power in the channel being measured by a low-gain detector and the power in the noise being measured by a high-gain detector. A processor receives the detector outputs, calculates OSNR, and controls the tunable components.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.