Polarization dependence of 133 Cs 6S 1/2 -6P 3/2 -11S 1/2 electromagnetically induced transparency at room temperature.

The effect of polarization on the ladder-type electromagnetically induced transparency (EIT) spectra of ¹³³ Cs atoms at room temperature for the transitions 6 ² P _1/2 -6 ² P _3/2 -11 ² S _1/2 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.