Characterization of a stress-applied polarization-maintaining (PM) fiber through photoelastic tomography

An accurate two-dimensional (2-D) axial stress profile of a polarization-maintaining (PM) fiber was determined using high-resolution photoelastic tomography. Likewise, determining all of the stress components of the fiber and the complete expression of stress-induced anisotropy was demonstrated. For the first time, we have expressed the anisotropy of a PM fiber in terms of birefringence distribution, and we have displayed the trajectories of principal axes on the cross section of the fiber. Mode coupling between the two orthogonal polarization modes due to the asymmetric stress applying parts of the PM fiber was also analyzed using an approximated coupled mode equation.