Photonic entanglement is central resource to quantum information sciences, such as quantum communication and quantum computation. The entangled photons generated in conventional spontaneous parametric down-conversion usually yield THz bandwidth which becomes very dim in many applications call for narrow-band entanglement sources. Here we demonstrate the polarization-entanglement photon source with counterpropagating phase matching, which results in an inherent bandwidth of 7.1 GHz at telecom wavelength. The entanglement is measured to violate the Bell inequality by up to 18.5 standard deviations, with Clauser–Horne–Shimony–Holt S-parameter of 2.720±0.039. The quantum state tomography further characterizes the entanglement, with fidelity F=(95.71±0.61)%.
Narrow-band source of polarization-entangled photons with counterpropagating domain engineering
Published: 17 June 2019 by MDPI AG in 2019 Advances in Quantum Engineering International Meeting session Quantum Communication and Quantum Cryptography
Keywords: entangled photon source；narrow-band photon；counter-propagation phase matching；