  In this paper, the generation of polarization entangled photon pairs at 1.5
{\mu}m is experimentally demonstrated utilizing a polarization maintaining
all-fiber loop, consisting of a piece of commercial polarization maintaining
fiber and a polarization beam splitter/combiner with polarization maintaining
fiber pigtails. A quantum state tomography measurement is performed to analyze
the entanglement characteristic of the generated quantum state. In the
experiment, a polarization entangled Bell state is generated with a
entanglement fidelity of 0.97+/-0.03 and a purity of 0.94+/-0.03 demonstrating
that the proposed scheme can realize polarization entangled photon pair
generation with polarization maintaining property which is desired in
applications of quantum communication and quantum information.
