  This work continues a series of papers where we propose an algorithm for
quasioptical modeling of electromagnetic beams with and without mode
conversion. The general theory was reported in the first paper of this series,
where a parabolic partial differential equation was derived for the field
envelope that may contain one or multiple modes with close group velocities.
Here, we present a corresponding code PARADE (PAraxial RAy DEscription) and its
test applications to single-mode beams in vacuum and also in inhomogeneous
magnetized plasma. The numerical results are compared, respectively, with
analytic formulas from Gaussian-beam optics and also with cold-plasma ray
tracing. Quasioptical simulations of mode-converting beams are reported in the
next, third paper of this series.
