Abstract

Two-photon spectroscopy has a unique property in cold, trapped atoms: the ability for atoms to absorb either copropagating or counterpropagating photons and still remain Doppler free, but with different recoil distributions. This can allow information to be gathered involving recoil and velocity distributions of the trapped atoms. Cold atoms also provide long interaction times and, hence, narrow linewidths. Nonlinear, two-photon spectroscopy of cold cesium atoms in a magneto-optical trap (MOT) is investigated for the 6S_½ → 12S_½ transition at 674.1 nm. Since this transition is detuned by ~180 nm from any intermediate level, it is very weak, requiring large laser intensities to drive the transition.

© 1997 Optical Society of America