Simulating Bell inequality violations with classical optics encoded qubits

We present here a classical optics device based on an imaging architecture as an analogy of a quantum system where the violation of the Bell inequality can be evidenced. Quantum states are encoded using an electromagnetic wave modulated in amplitude and phase. Unitary operations involved in the measurement of the observables are simulated with the use of a coherent optical processor. The images obtained in the output of the process contain all the information about the possible outcomes of the joint measurement. By measuring the intensity distribution in the image plane we evaluate the mean values of the simulated observables. The obtained experimental results show how some correlations of Clauser-Horne-Shimony-Holt-type exceed the upper bound imposed by the local realism hypothesis as a consequence of the joint effect of entanglement and two-particle interference. (C) 2010 Optical Society of America