Low polarization mode dispersion measurements in ad hoc drawn spun fibers

Polarization mode dispersion causes significant impairment in high bit-rate optical telecommunications systems. It is well accepted that polarization mode dispersion can be strongly reduced by spinning the fiber while drawing, even if a comparison between theoretical predictions and experimental evidence has never been reported. In this paper we focus on the polarization mode dispersion measurement of ad hoc drawn periodically spun fibers, providing a first although preliminary experimental analysis of the spin induced differential group delay reduction. When measuring very low differential group delays as in the case of spun fibers, standard techniques are affected by rather high uncertainties. This problem is usually solved repeating several times the measurements while randomly perturbing the fiber. We support experimentally this method by means of polarization sensitive reflectometric measurements.