ABSTRACT: We report the development of a fiber-based single-spatial-mode source of photon-pairs where the efficiency of extracting photon-pairs is improved over a previous source  through the use of fiber-end expansion and Bragg filters. This improvement in efficiency enabled a spectrally bright and pure photon-pair source having a small second-order correlation func-tion (0.03) and a raw spectral brightness of 44,700 pairs s −1 nm −1 mW −1 . The source can be configured to generate entangled photon-pairs, character-ized via optimal and minimal quantum state tomography, to have a fidelity of 97% and tangle of 92%, without subtracting any background., "A versatile waveguide source of photon pairs for chip-scale quantum information processing," Opt. Express 17, 6727-6740 (2009)..5-µm band quantum-correlated photon pair generation in dispersion-shifted fiber: suppression of noise photons by cooling fiber," Opt. Express 13, 7832-7839 (2005). 14., "Fiber-based telecom-band degenerate-frequency source of entangled photon pairs," Opt. Lett. 31, 2798-2800 (2006).
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