Experimental Observation of Autler?Townes Splitting in Sub-Doppler Selective Reflection Spectroscopy

We present an experimental study of Autler–Townes splitting of non-linear selective reflection spectroscopy in a Λ-type driven three-level system. The sub-Doppler reflection spectroscopy is observed and the Autler–Townes splitting is measured as functions of the different coupling laser intensity and detuning. The coherent drive splits the excited state into two dressed states and an Autler–Townes splitting emerges in the probe reflection. The experimental results are in good agreement with theoretical fit.