Phase space properties of light within the generalised Dicke model

The ground state of 3-level atoms in the V-configuration interacting dipolarly with two modes of an electromagnetic field is determined. By means of the fidelity concept, the quantum crossovers, called also quantum phase diagrams for a finite number of particles, are obtained. The behaviour of light traversing these finite quantum phase diagrams is studied through the calculation of their corresponding Wigner and Husimi functions. This allows us to predict the unimodal and bimodal character of light when it is in the normal or superradiant regions.