Using polarimetric optical time domain reflectometry to extract spun fibre parameters

The spatial frequencies present in a polarimetric optical time domain reflectometer trace of spun fibre are a strong function of external fibre twist and the initial spinning parameters used to fabricate the fibre. It is shown how analysis of the spatial frequencies in the POTDR trace in conjunction with the backscattered state of polarisation evolution can determine the spinning parameters of the spun fibre. This technique can be used to check whether the intended spinning parameters are in fact being impressed on the fibre during manufacture