Temperature dependence of electromagnetically induced transparency in a Cs atomic vapor cell

Abstract

The temperature dependence of electromagnetically induced transparency (EIT) in a Cs atomic vapor cell was investigated. A probe laser beam frequency was scanned around the resonance frequency of the transition line 6S(1/2), F = 3 -> 6P(3/2), F' = 4 while the coupling beam frequency was locked to the transition line 6S(1/2), F = 4 -> 6P(3/2), F' = 4. In order to analyze the temperature dependence of the EIT signal quantitatively, we calculated the dispersion slope of the EIT signal at the resonance frequency of the probe beam by taking the 2(nd) derivative of the measured EIT signal. We found that there existed an optimum temperature at which the dispersion slope had a maximum value. This temperature dependence of the EIT signal was well explained by the calculated results considering the Doppler effect and the atomic coherence relaxation due to atomic collisions.