Brillouin gain variation due to a polarization-state change of the pump or Stokes fields in standard single-mode fibers

Abstract

The effect of pump or Stokes field polarization-state changes on Brillouin gain is investigated in standard (non-polarization-maintaining) single-mode fibers with a modal birefringence of ~10⁻⁷. The Brillouin gain change due to polarization azimuth variation of the input pump or Stokes field reaches ±31% of the average gain expected for a completely scrambled polarization state. This polarization effect on the Brillouin gain may lead to cross-talk fluctuation in bidirectional coherent transmission systems and to degradation of Brillouin amplifier performance.