Quantum properties of one-atom maser radiation in the presence of thermal photons

The effect of thermal photons on the radiative properties of a one-atom maser is investigated. Stationary Pand Qdistribution functions are determined analytically in the approximation of strong interaction between an atom and a cavity field mode. The generation conditions are found for a one-atom maser. It is shown that taking into account thermal photons leads to a decrease in the threshold value of incoherent pumping. It is demonstrated that generation may occur in the absence of population inversion in the atomic subsystem and when losses exceed the intensity of incoherent pumping. A formula is proposed for the Fano factor of a one-atom maser in the form of the sum of the Fano factors of the microcavity radiation in the absence of thermal photons and the thermal radiation.