[en] In this paper we will show some recent experiments performed in the 'Carlo Novero' labs of the Optics Division of the National Institute of Metrological Research (INRIM, Torino, Italy), in order to discriminate between Standard Quantum Mechanics and some specific, restricted class of Hidden Variable Theories (HVTs). The first experiment will be on the testing of two restricted Local Realistic Theories (LRTs), properly built to describe polarization entangled photons experiments, whose inequalities are not affected by the detection loophole. The second and third experiments instead will perform the Alicki - Van Ryn non-classicality test on single particles, by means of two different setups based on heralded single photon sources.