Effects of spin process on birefringence strength of single-mode fibers.

Spin process is the most effective and diffused way to reduce polarization mode dispersion in single-mode optical fibers. All theoretical models adopted so far to describe spun fibers assume that the only effect of spin is to rotate fiber birefringence, without affecting its strength. Yet, experimental analyses of this hypothesis are controversial. In this paper, we report on an extensive experimental characterization of birefringence in spun and unspun fibers. Results indicate that the spinning process has no instantaneous effect on birefringence strength, regardless of the kind of fiber; nevertheless, there might be a small average effect on G.652 fibers.