Patent · US Expired

OSNR monitoring method and apparatus for the optical networks

US7177541B2 · kind B2 · utility

2Cited by
5References
7Claims
0Family size

Assignee

Inventors

Key dates

Filing dateNov 9, 2001
Grant dateFeb 13, 2007
Priority date—
Expiry dateApr 5, 2023

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH04B10/07953
  • WIPO fieldTelecommunications
  • WIPO sectorElectrical engineering

Abstract

It is disclosed that a method and apparatus that automatically monitors each channel's optical signal-to-noise ration (OSNR) using optical filter and polarization extinction method in wavelength division multiplexing (WDM) scheme-based optical transmission systems. OSNR is simply measured using optical filter by comparing amplified spontaneous emission (ASE) over the signal band, of which bandwidth has changed, while leaving signal intensity intact, with that original signal and, OSNR measurement is allowable over a wider range of OSNR by minimizing the ratio of signal to ASE over the signal band using polarization extinction method.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.