SQUEEZED STATES WITH THERMAL NOISE .1. PHOTON-NUMBER STATISTICS

We investigate a free monochromatic electromagnetic field which is the superposition of a squeezed thermal radiation and a coherent one. The main tool in our analysis is the characteristic function that has a G aussian form. We establish an analytic formula for an arbitrary correl ation function, as well as its strong-squeezing limit. Besides the usu al quasiprobability densities, the coherent-state, number-state, coord inate, and momentum representations of the density operator are derive d. We point out the nonclassical oscillations of the photon-number dis tribution and find its generating function. Collaterally, displaced th ermal states and squeezed thermal states are revisited as nontrivial p articular cases. We examine finally the squeezing properties of the fi eld using the distribution functions of the quadratures.