TIA 455-175 : B2003

A procedure is described for the measurement of chromatic dispersion of single mode optical fibers over the 1.0 to 1.7 micrometer wavelength range. The dispersion coefficient at a particular wavelength is determined from the differential group delay between two closely spaced wavelengths. In this procedure, a modulated light source is coupled into the fiber under test, and the phase of the modulated signal exiting the fiber at a first wavelength is compared with the phase at a second wavelength. Average chromatic dispersion over the interval between the two wavelengths is determined from the differential phase shift, wavelength interval, and fiber length.