Apparatus and method for measuring the chromatic dispersion of an optical transmission link

Abstract

In a method for measuring the chromatic dispersion of a light waveguide an amplitude modulated broadband optical signal is fed into the optical transmission link to be measured, the transmitted signal is separated into a reference path, in which the modulation frequency is demodulated out of the transmitted signal, and a measuring path, in which the transmitted signal is demodulated at several optical frequencies respectively, and the chromatic dispersion of the optical transmission link is determined from the phase differences between the several demodulated signals of the measuring path and the demodulated signal of the reference path. The corresponding apparatus comprises an amplitude modulated, broadband light source at the input side of the light waveguide to be measured, a device which separates the transmitted optical signal into a reference path and a measuring path, a tuneable narrowband optical filter in the measuring path, a photo detector in the reference path and in the measuring path respectively and a phase measuring device provided at the output side of the two photo detectors for determining the phase differences respectively present between the reference and measuring path, from which the chromatic dispersion of the optical transmission link can be determined.

Dependencies are inferred from the claim text.