Higher fidelity source of entangled photon-pairs from a photonic crystal fiber via mode expansion and Bragg filtering

摘要

We report the development of a fiber-based single-spatial-mode source of photon-pairs where the efficiency of extracting photon pairs is 14x higher than a previous implementation [16]. This critical improvement in efficiency enabled a spectrally bright and pure photon-pair source having a small second-order correlation function (0.03) and a raw spectral brightness of 44,700 pairs/(s nm mW). The source can be configured to generate entangled photon-pairs, characterized via optimal and minimal quantum state tomography, to have a fidelity of 97% and tangle of 92%, without correcting for accidentals.