Optical saturation resonances in radio-frequency-dressed molecules

Abstract
In an optical radio-frequency double-resonance experiment on NO2 optical saturation resonances are observed. These resonances appear superimposed on the normal magnetic resonance spectrum. With increasing laser light intensity they change the resonance spectrum considerably. We present a model to describe the observed saturation phenomena: The resonances are attributed to the interaction of two optical photons and at least one radio-frequency photon with the molecule. The theory shows that saturation resonances appear in the population and in the coherence of the dressed-molecule levels in agreement with the experimental results.