High-quality fiber-optic polarization entanglement distribution at 1.3μm telecom wavelength

Tian Zhong, Xiaolong Hu, Franco N.C. Wong, Karl K. Berggren, Tony D. Roberts, and Philip Battle

Abstract

We demonstrate high-quality distribution of 1.3μm  polarization-entangled photons generated from a fiber-coupled periodically poled KTiOPO₄ waveguide over 200m fiber-optic cables. Time-multiplexed measurements with a 19% efficient superconducting nanowire single-photon detector at the remote location show a detected flux of 5.8 pairs /s at a pump power of 25 μW and an average two-photon quantum-interference visibility of 97.7% without subtraction of accidentals