%0 Journal Article %T Nonlinear, ground-state, pump-probe spectroscopy %A P. R. Berman %A B. Dubetsky %J Physics %D 2000 %I arXiv %R 10.1103/PhysRevA.62.053412 %X A theory of pump-probe spectroscopy is developed in which optical fields drive two-quantum, Raman-like transitions between ground state sublevels. Three fields are incident on an ensemble of atoms. Two of the fields act as the pump field for the two-quantum transitions. The absorption or gain of an additional probe field is monitored as a function of its detuning from one of the fields which constitutes the pump field. Although the probe absorption spectrum displays features common to those found in pump-probe spectroscopy of single-quantum transitions, new interference effects are found to modify the spectrum. Many of these features can be explained within the context of a dressed atom picture. %U http://arxiv.org/abs/physics/0004046v3