Journal of Experimental and Theoretical Physics
Coulomb broadening of the peak of electromagnetically induced transparency in plasma
Sergei A Babin, М. Г. Степанов, Dmitry V. Churkin, David A. Shapiro
Abstract
We have measured the shape of the Autler-Townes doublet and the peak of electromagnetically induced transparency (EIT) under plasma conditions. We compare the experimental results with the calculated spectrum of the probe field of a three-level ArII Λ-scheme by taking into account Coulomb collisions. We show that the Coulomb broadening of the EIT peak is small (less than 40%), while the saturation resonance is broadened under the experimental conditions by a factor of 3. In contrast to the saturation resonance attributable to the Bennett dip in the velocity distribution of the population, the EIT peak is a coherent effect and is broadened mainly through Coulomb dephasing.