Accumulation of polarization-mode dispersion in cascades of compensated optical fibers

First-order compensation of polarization-mode dispersion (PMD) leaves residual, higher order PMD. We analyze the accumulation of residual distortion in cascades of compensated fibers. Total distortion is calculated and limitations on the total propagation length are given. While compensation can greatly extend the total propagation distance, its effectiveness diminishes rapidly as the bandwidth is increased.