Optical tests of Bell's inequalities not resting upon the absurd fair sampling assumption

Abstract

A simple local hidden-variables model is exhibited which reproduces the results of all performed tests of Bell\'{}s inequalities involving optical photon pairs. For the old atomic-cascade experiments, like Aspect\'{}s, the model agrees with quantum mechanics even for ideal set-ups. For more recent experiments, using parametric down-converted photons, the agreement occurs only for actual experiments, involving low efficiency detectors. Arguments are given against the fair sampling assumption, currently combined with the results of the experiments in order to claim a contradiction with local realism. New tests are proposed which are able to discriminate between quantum mechanics and a restricted, but appealing, family of local hidden-variables models. Such tests require detectors with efficiencies just above 20%.