  We have examined the frequency spectrum of the blue light generated via
four-wave mixing in a rubidium vapor cell inside a ring cavity. At high atomic
density and input laser power, two distinct frequency components separated by
$116 \pm 4$ MHz are observed, indicating alternate four-wave mixing channels
through the $6p_{3/2}$ hyperfine states. The dependence of the generated light
on excitation intensity and atomic density are explored, and indicate the
primary process has saturated. This saturation results when the excitation rate
through the 6p state becomes equal to the rate through the 5p state, giving no
further gain with atomic density while a quadratic intensity dependence
remains.
