Nonclassicality of bright Greenberger-Horne-Zeilinger–like radiation of an optical parametric source

With the emerging possibility to obtain emissions of triples GHZ-entangled photons via a direct parametric generation we study here bright this kind which involve higher order two triples, three etc. Such states would constitute natural generalization four mode (two beams plus polarization) squeezed vacuum. We have beam process emission generalized GHZ states, are superpositions one, two, three, and so on entangled photons. show how avoid technical difficulties related with straight ahead usual description down conversion. Using Pade approximation turn first terms non-converging perturbation expansion into elements conversing series. This allows us non-classicality new states.