Two-channel Raman-coupling and micromaser model

The Raman interaction including a pump-Stokes channel and a pump-anti-Stokes channel is studied in the micromaser context. We show that when the field operators are transformed in a squeezed basis, the effective Hamiltonian behaves as a Jaynes-Cummings model. In the case where atoms are injected through the cavity from their ground states, we show that atoms can absorb photons from one of the squeezed modes. This makes the fluctuations of a two-mode quadrature phase of the Stokes and anti-Stokes fields decrease rapidly and eventually saturate to a value which is well below the vacuum fluctuation level. We also discuss the photon probability distribution of the steady state field.