Observation of doubly dressed states in ladder-type electromagnetically induced transparency system

Doubly dressed states in a ladder-type two-photon, three-level coupling system are observed in our system. The quantum nature of the EIT system significantly suppresses Doppler broadening. The experiments were performed on a room-temperature atomic cesium cell .The cesium atoms are excited by two linearly polarized fields with parallel polarization. The spacing of the EIT doublet is strongly consistent with the theoretical description of the Mollow spectrum, and the numerical simulation demonstrates that Doppler broadening can be greatly reduced using this detection technique.