High-flux source of polarization-entangled photons from a periodically poled KTiOPO4 parametric down-converter

We have demonstrated a high-flux source of polarization-entangled photons using a type-II phase-matched periodically poled KTiOPO4 parametric down-converter in a collinearly propagating configuration. We have observed quantum interference between the single-beam down-converted photons with a visibility of 99% together with a measured coincidence flux of 300 s(-1)/mW of pump. The Clauser-Horne-Shimony-Holt version of Bell's inequality was violated with a value of 2.711 +/- 0.017.