Quantum interference and non-locality of independent photons from disparate sources

We quantitatively investigate the non-classicality and non-locality of a whole new class of mixed disparate quantum and semiquantum photon sources at the quantum-classical boundary. The latter include photon-added thermal and photon-added coherent sources, experimentally investigated recently by Zavatta et al (2009 Phys. Rev. Lett. 103 140406). The key quantity in our investigations is the visibility of the corresponding photon-photon correlation function. We present explicit results on the violations of the Cauchy-Schwarz inequality-which is a measure of non-classicality-as well as of Bell-type inequalities.