Experimental violations of Bell's inequalities with time-bin and polarization entanglement Violazione delle disuguaglianze di Bell con entanglement in polarizzazione e time-bin

In this thesis activity the candidate has explored the main aspects of Bell Inequalities theory and eventually executed an experimental Violation test. This work contains a brief overview of the theoretical aspects around Bell Inequalities: the doubts arisen by Einstein, Podolski and Rosen about Quantum Theory completeness; the hidden variable theories and the bounds on classical correlations; quantum correlations and violation of Bell inequalities; the response given by Bell to the EPR paradox by introducing its famous theorem. In addition, the entanglement phenomenon has been studied, in particular in those dof that are given an important role in the violation of Bell Inequalities. Some documentation work was also done on non linear optics in order to understand fundamental effects that is common practice to exploit in the photon entanglement generation: SHG for the pump photons, SPDC in non-linear crystals. Moreover, the candidate also explored in this thesis some issues more closely related to the experimental aspect:loopholes that could affect the integrity of Bell inequalities proofs; efficiency threshold estimates regarding detection loophole; loophole-free configurations. Eventually, here in this report are also showed, along with the experimental setup brief description and some comments on the apparatus and its setting, the results of an experimental test of the CHSH inequality violation using photons entangled at first in polarization and then in a time-bin entanglement configuration.