Dispersion measurement in optical networks

US6734955B2 · kind B2 · utility

Inventors

• Mark Wight · Ottawa, CA
• Andreas Sizmann · Munich, DE
• Mei Du · Scotch Plains, US
• Alan Glen Solheim · Gatineau, CA

Key dates

• Filing date: Jan 28, 2002
• Grant date: May 11, 2004
• Expiry date: Jul 26, 2022

Classification

• Technology area (CPC G): Physics
• CPC primary: G01M11/335
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

A device for measuring dispersion of a link between two switching nodes of an optical network comprises a phase measuring unit PMU for determining a first phase of a data signal traveling on a first wavelength &lgr;1, and a second phase of the same data signal traveling on a second wavelength &lgr;2, received consecutively over the link under measurement. A dispersion measurement controller controls operation of the phase measuring unit and characterizes the dispersion of the link at a wavelength of interest &lgr;=(&lgr;1+&lgr;2)/2, based on the first and second phases. The PMU includes a frame detector for determining a first and a second rotation signal indicative of the digital offset between the first and second test clocks with a respective frame start, and a phase detector for measuring the phase of these test clocks with respect to a static reference. The static reference is provided by the same data signal transmitted continuously over a reference wavelength. The test and reference clocks are 1:n divided to extend the range of the measurement. A method for characterizing the dispersion of a link of an optical network is also provided.