System and method to determine chromatic dispersion in short lengths of waveguides using a common path interferometer

An interferometric method for obtaining a measure of the chromatic dispersion of a waveguide under test comprising the steps of:

• a. connecting a radiation source to a means for separating incident and reflected waves, said means for separating incident and reflected waves having an output arm comprising a launch waveguide terminating at an angle polished connector;
• b. placing a first facet of the waveguide under test adjacent to the angle polished connector;
• c. connecting the means for separating incident and reflected waves to an optical detector;
• d. generating a radiation emission at a plurality of wavelengths from the radiation source;
• e. recording an Fabry-Perot interferogram consisting of two waves with the optical detector wherein a first wave is a reflection of the radiation emission from the first facet of the waveguide under test and a second wave is a reflection of the radiation emission from a second facet of the waveguide under test;
• and
• f. determining an average fringe period of the Fabry-Perot interference pattern for at least three of the plurality of wavelengths and obtaining a first and second derivative of a propagation constant from the average fringe periods, the measure of chromatic dispersion being obtainable based on the first and second derivative of the propagation constant.