Quantum noise reduction in the non-degenerate three-level micromaser

We present the theory of a micromaser operating on a cascade three-level atomic transition, which is coupled to two cavity modes satisfying the resonance condition. A numerical approach is employed to integrate the master equation describing the microwave field, allowing us to obtain the semiclassical regime in the limit of large mean photon numbers. We show that the transfer rate from the excited atomic stare is very close to 100% over a large interval of variation of the interaction time. The atom-held interaction time may be chosen so as to avoid transitions to the intermediate atomic state when in steady-slate operation. In this case, the two cavity modes have nearly the same photon statistics, and the fluctuations in the difference of intensities may be reduced by up to 50% below the classical limit. The intensity correlation between the two cavity modes originates from the possibility of controlling the interaction time, rather than from the simultaneous generation of 'twin' photons in a two-photon transition.