Polarization-entangled photon pair source using beam displacers and thin crystals

We present an experimental implementation of a polarization-entangled photon pair source based on beam displacers. The down-converted photons are emitted via spontaneous parametric down-conversion in a non-degenerate and type-0 process. We obtain a state fidelity of F=0.975±0.004 and violate a Clauser-Horne Shimony-Holt inequality with S=2.75±0.01. Our source also uses thin crystals for applications in quantum imaging, taking advantage of the large number of spatial modes. With this configuration, we obtain 550±12 spatial modes.