TY - JOUR AU - Salem, Reza AU - Lenihan, Anthony S. AU - Carter, Gary M. AU - Murphy, Thomas E. TI - Techniques for Polarization-Independent Cross-Phase Modulation in Nonlinear Birefringent Fibers JO - IEEE J. Sel. Topics Quantum Electron. VL - 14 IS - 3 SP - 540 EP - 550 PY - 2008 DO - 10.1109/JSTQE.2007.915391 AB - We present a theoretical, numerical, and experimental investigation of the polarization dependence of cross-phase modulation in nonlinear birefringent fibers. Two new methods are described for producing a polarization-independent spectral shift through cross-phase modulation of a weak probe signal by a copropagating strong optical pulse. The birefringence of the fiber and spectral separation between the pump and probe signals are shown to play a critical role in determining the polarization dependence of the cross-phase modulation process. The methods are experimentally verified in two different highly nonlinear fibers, and are used to achieve polarization-independent optical switching at speeds of up to 160 Gb/s. ER -