Optimized spinning design for low PMD fibers: An analytical approach

It is known that the differential group delay (DGD) due to polarization mod e dispersion (PMD) can be effectively reduced by spinning the fiber during drawing. In this paper, we propose an analytical approach that allows optim ization of the spinning design. The fundamental idea is that, in the absenc e of polarization coupling, an optimized spinning profile can balance the e ffects of the intrisic linear birefringence so that the differential group delay can be forced to be periodic and, consequently, have a limited amplit ude as a function of distance. Our approach is independent of the spin prof ile. In other words, with a fixed set of parameters that characterize a par ticular spin function, we are able to find analytically the values correspo nding to a periodic DGD in a deterministic regime. Numerical results based on waveplate model confirm the analytical prediction and show that PMD can be reduced by about two orders of magnitude with respect to the same fiber without spinning, even after the introduction of random polarization coupli ng.