High-flux, high-visibility entangled photon source obtained with a non-collinear type-II PPKTP crystal pumped by a broadband continuous-wave diode laser.

We demonstrated a high-brightness, polarization-entangled bi-photon source generated in a type-II phase-matched non-collinear PPKTP crystal pumped by a 405 nm continuous-wave (cw) broadband diode laser. Basing on the single-pass configuration, we investigated the distribution characteristics of the bi-photon cone and the wavelength tunability with crystal temperatures. Overcoming the degradation of the bi-photon generation rate and the spectral correlation induced by the broadband pump laser, we obtained a bi-photon generation rate of 7. 48 × 10 3/s/mW/nm and an interference visibility over 95% via a Hong–Ou–Mandel (HOM) configuration. We established a theoretical model to address the bi-photon time-delayed HOM dip pumped by the broadband cw diode laser in spontaneous parametric down-conversion and obtained the complete analytic solution of the bi-photon coincidence counting rates. • The manuscript presented a detailed experimental and theoretical study of the fundamental properties of bi-photon pairs source generated in a non-collinear type-II PPKTP crystal. • Based on a Hong–Ou–Mandel (HOM) interference configuration, a high-flux bi-photon generation rate of 7.48 × 103/s/mW/nm and a high interference visibility over 95% are obtained by using of a broadband diode laser. • A reasonable theoretical model is established to address the bi-photon time-delayed HOM-dip pumped by the broadband cw diode laser via the spontaneous parametric down-conversion (SPDC). The complete analytic solution of the coincidence counting rate of bi-photons is obtained. [ABSTRACT FROM AUTHOR]