New experimental test of Bell inequalities by the use of a non-maximally   entangled photon state
  We report on the first realisation of a test of Bell inequalities using non-maximally entangled states. It is based on the superposition of type I parametric down conversion produced in two different non-linear crystals pumped by the same laser, but with different polarisations. We discuss the advantages and the possible developments of this configuration. 
G. Brida, M.Genovese, C. Novero and E. Predazzi