Polarization dependence of Cs 6S-6P-11S electromagnetically induced transparency at room temperature.

The effect of polarization on the ladder-type electromagnetically induced transparency (EIT) spectra of Cs atoms at room temperature for the transitions 6P-6P-11S is experimentally studied. The entire spectra with additional peaks arising from the Doppler effect are observed. As the relative angle between the probe's and coupling's plane of polarization arranges at 0, 45, and 90, the peak height ratio of 44'3" to 44'4" increases by more than 7 times with corresponding values of 0.19, 0.69, and 1.4. Meanwhile, that of 45'4" to 44'4" are found to be 0.61, 0.87, and 1.23 (doubled), respectively. A theoretical model built to explain the experimental results with the considerations of optical pumping effect, two-photon transition probability, dephasing rate, and integration all over the velocity distribution. The simulation and experimental results are well-agreed.