Micromaser Revisited: Sub-Poissonian Fields from Poissonian Pumping

We perform quantum trajectory simulations of the micromaser/laser with Poissonian pump, lifting all restriction on the number of simultaneously interacting atoms. For mean numbers of intracavity atoms between zero and two, highly sub-Poissonian fields are obtained from the Poissonian pumping, with a Mandel Q parameter inside the cavity below -0.6 under suitable conditions. Simulation of a Hanbury Brown and Twiss-type measurement performed on the cavity emissions recovers the intracavity value of the Mandel Q parameter from the intensity correlation function of the output photon stream.