  Atom interferometers in optical cavities benefit from strong laser
intensities and high-quality wavefronts. The laser frequency pairs that are
needed for driving Raman transitions (often generated by phase modulating a
monochromatic beam) form multiple standing waves in the cavity, resulting in a
periodic spatial variation of the properties of the atom-light interaction
along the cavity axis. Here, we model this spatial dependence and calculate
two-photon Rabi frequencies and ac Stark shifts. We compare the model to
measurements performed with varying cavity and pulse parameters such as cavity
offset from the carrier frequency and the longitudinal position of the atom
cloud. We show how setting cavity parameters to optimal values can increase the
Raman transition efficiency at all positions in the cavity and nearly double
the contrast in a Mach-Zehnder cavity atom interferometer in comparison to the
unoptimized case.
