scope:

Intent

This test method describes a procedure for measuring the polarization-mode dispersion (PMD) of single-mode optical fibers. The measurement result is obtained from a single series of Stokes parameter measurements performed at intervals across a wavelength range. It can be applied to both short and long fibers, regardless of the degree of polarization mode coupling. Under some circumstances, repeated measurements are necessary to achieve satisfactory precision using this FOTP; see Annex A.

The method is restricted to wavelengths greater than or equal to that at which the fiber is effectively single-mode.

The method provides a means to calculate the differential group delay (DGD) as a function of optical frequency (wavelength) from the measurements. On the basic of providing the full polarimetric characteristics of the fiber, this method is considered as a reference test method (RTM) against which any other method shall be compared to in case of a dispute or for calibration.

The method provides two equivalent ways to make the DGD analysis. The Jones matrix eigenanalysis (JME) determines the DGD from the wavelength dependence of the Jones matrix, a 2x2 complex matrix that describes the optical transfer function of the test device. The Poincaré sphere analysis (PSA) determines the DGD from the wavelength dependence of the output state of polarization (SOP) in the context of the Poincaré sphere and the Stokes parameters. In both cases, the wavelength dependence is determined over a specific wavelength interval, by measurements at the start and end of that interval.