SATURATED ABSORPTION EXPERIMENTS ON A DRESSED MOLECULE - APPLICATION TO THE SPECTROSCOPY OF THE UPSILON-6 BAND OF CH3I

Inverted Lamb dips involving infrared-radio-frequency two-photon and multiphoton processes have been observed for intracavity CH3I molecules using CO2 and N2O lasers. The Doppler-free resonances have been studied for radio-frequency radiation with a frequency lower or comparable to the CH3I nuclear quadrupole splitting. Velocity-tuned Doppler-free resonances resulting from various coupling of the different multiphoton processes have also been detected. A dressed-molecule formalism has been applied to describe the Doppler-free resonances of the molecule dressed with the radio-frequency field. Accurate molecular constants in the ν6 state of CH3I have been determined from the Doppler-free measurements of the ν6O vibration rotation transitions. © 1979 The American Physical Society.