A Michelson interferometer with a phase-conjugate mirror (PCM) is described and discussed. The behavior of phase conjugate mirrors is discussed and the result of an experiment with a Michelson interferometer with a phase-conjugate mirror is described and commented. This interferometer has been proposed to be used to test the intrinsic non-locality of quantum mechanics. In this paper a new experimental setup to study the one-way velocity of light is proposed, which uses this new interesting device.

By following the analysis of De Caro and Garuccio [Phys. Rev. A 54, 174 (1996)], we show that the factorable state vector produced with a beam-splitter set on the paths of parametric down-converted photons violates some new inequalities that we deduce from local realism. These inequalities are more stringent than those used up to now in the discussion of such phenomena.