  Polarization-entangled photon pair generation based on two scalar scattering
processes of the vector four photon scattering has been demonstrated
experimentally in high nonlinear microstructure fiber with birefringence. By
controlling the pump polarization state, polarization-entangled Bell states can
be realized. It is provides a simple way to realize efficient and compact fiber
based polarization-entangled photon pair sources.
