Patent ID: 8135275
Filing Date: 2012-03-13
Classification: G01M,H04B

Abstract:
1. A method for measuring chromatic dispersion of a selected wavelength channel in an optical fiber link, which transmits a plurality of wavelength division multiplexed (WDM) channels, comprising: a) producing an optical signal at a selected wavelength within the selected wavelength channel; b) modulating the optical signal with a first high frequency modulation signal having a predetermined frequency and amplitude to generate first and second sideband test signals comprising modulated light symmetrically disposed about the selected wavelength within the selected wavelength channel; c) modulating the first and second sideband test signals with a second lower frequency modulation signal for impressing a low frequency amplitude modulation on the first and second sideband test signals; d) coupling the first and second sideband test signals into a first point in the optical fiber link; and e) measuring a differential time delay between the modulated light in the first and second sideband test signals at a second point in the optical fiber link in order to determine the chromatic dispersion in the selected wavelength channel of the optical fiber link.