Polarization cross saturation in an Er^3+-doped fiber ring laser

The cross saturation between the polarization eigenmodes is measured in a unidirectional Er(3+) -doped fiber ring laser in which the population inversions for the polarization components are decoupled only by polarization hole burning. A coupling factor of beta = 0.80 +/- 0.01 is obtained from measurements of the polarization antiphase dynamics in the laser.