Analytical treatment of randomly birefringent periodically spun fibers

Abstract

Abstract-Spun fibers are increasingly used in telecommunication systems because their polarization-mode dispersion (PMD) is lower than that in unspun fibers. In this paper, we investigate the effects of a periodic spin on the PMD of fibers with randomly varying birefringence. Numerical simulations show that when the spin period is of the same order as or larger than the beat length, the mean differential group delay of a spun fiber depends on the model used for the random birefringence. We then carry out a general theoretical analysis using the second Wai-Menyuk model, which is the only model of fiber birefringence to date that is consistent with polarization optical time domain reflectometry data. Finally, we consider some particular regimes by means of a perturbative approach.Index Terms-Beat length, birefringence correlation length, differential group delay, fiber birefringence, polarization-mode dispersion (PMD), spun fibers.

The PMD of sinusoidally spun fibers in the presence of random birefringence perturbations

“…We first investigate the PMD reduction as a function of both the fiber parameters and the spin amplitude, and then compare the evolution of the probability density function (pdf) of the DGD along fiber length in spun fibers to that of standard fibers. The degree of PMD reduction through spinning is often specified through the spin-induced reduction factor (SIRF), defined by Pizzinat et al (2003b):…”

Low-PMD spun fibers

“…(23) does not always converge depending on the birefringence and spin parameters. In general the solution of the truncated system is much faster than performing simulations, but when LF approaches, or is bigger than LB, truncating the system gives incorrect results [34]. The negative consequence of this discussion is that it has not been possible to carry out useful analytical results with the RMM.…”

“…The analysis of spun fibers using the RMM starts by transforming the reference frame in order to compensate for the intrinsic rotation of the birefringence and for the rotation induced by the spin [34]. This task can be achieved by using the matrix…”

“…Actually, it may be shown that the iterative application of the generator to any new term to be found, leads to an infinite sequence of relationships that can be expressed recursively as follows [34]:…”

“…The solid curves, from the upper to the lower, refer to L F = 0.5, 1, 2, 3, 6, 16, and 50 m, respectively. Adapted from[34].…”