  We consider a single atom laser (microlaser) operating on three-level atoms
interacting with a two-mode cavity. The quantum statistical properties of the
cavity field at steady state are investigated by the quantum trajectory method
which is a Monte Carlo simulation applied to open quantum systems. It is found
that a steady state solution exists even when the detailed balance condition is
not guaranteed. The differences between a single mode microlaser and a two-mode
microlaser are highlighted. The second-order correlation function g^2(T) of a
single mode is studied and special attention is paid to the one-photon trapping
state, for which a simple formula is derived for its correlation function. We
show the effects of the velocity spread of the atoms used to pump the
microlaser cavity on the second-order correlation function, trapping states,
and phase transitions of the cavity field.
