  We describe a one-atom microlaser involving Poissonian input of atoms with a
fixed flight time through an optical resonator. The influence of the cavity
reservoir during the interactions of successive individual atoms with the
cavity field is included in the analysis. The atomic decay is also considered
as it is nonnegligible in the optical regime. During the random intervals of
absence of any atom in the cavity, the field evolves under its own dynamics. We
discuss the steady-state characteristics of the cavity field. Away from laser
threshold, the field can be nonclassical in nature.
