Method and apparatus of single-ended polarization mode dispersion measurement

A system for measuring a polarization mode dispersion (PMD) to characterize an optical fiber under test, the system comprising:

• a polarization-sensitive Optical Time Domain Reflectometer (POTDR) acquisition device connectable toward a proximal end of the optical fiber under test for performing a plurality of polarization-sensitive acquisitions toward the optical fiber under test, a distal end of said optical fiber under test being connected to a light reflector,
• wherein said POTR acquisition device is configured so that:
• each acquisition is performed by propagating in the optical fiber under test, a polarized test signal comprising a first series of repeated light pulses and detecting a corresponding polarization-analyzed return light signal coming back from the optical fiber under test and comprising back-reflected light from the light reflector, said return light signal comprising repeated reflected light pulses, wherein said repeated light pulses are together propagated in the optical fiber under test within a fiber round-trip time,
• each of said acquisitions is performed with a corresponding wavelength of said test signal,
• said plurality of polarization-sensitive acquisitions defines at least one pair of acquisitions performed with mutually different but closely-spaced wavelengths and substantially the same state of polarization (SOP), a center of the wavelengths defining a center wavelength for said at least one pair, and
• said plurality of polarization-sensitive acquisitions comprises a plurality of pairs of acquisitions performed with at least one of a plurality of mutually-different center wavelengths and a plurality of mutually-different states of polarization (SOP);
• and
• a processing unit receiving acquisition data and configured for:
• for each said acquisitions, averaging respective amplitudes of at least part of said repeated reflected light pulses to obtain a value of reflected power,
• for each said pairs of said acquisitions, computing a value of a difference, between the two values of reflected powers corresponding to said pair,
• computing a mean-square value of the computed values of difference over said at least one of a plurality of mutually-different center wavelengths and a plurality of mutually-different states of polarizations (SOPs);
• and
• from said mean-square value, calculating a value of the polarization mode dispersion of said optical fiber under test.