Autler–Townes doublet in the absorption spectra for the transition between excited states of cold cesium atoms

Autler-Townes splitting in absorption spectra of the excited states 6 ²P_3/2 - 8²S_1/2 of cold cesium atoms confined in a magneto-optical trap has been observed. Experimental data of the Autler–Townes splitting fit well to the dressed-atom theory, by which the fact of the cold atoms dressed by cooling/trapping laser beams is revealed. The results of the theoretical fitting with experiment not only told us the effective Rabi frequency cold atoms experienced, but also could be used for measuring the probability amplitudes of the dressed states.