Features of Magneto-Optical Resonances in an Elliptically Polarized   Traveling Light Wave
  The parameters of nonlinear absorption magneto-optical resonances in the Hanle configuration have been studied as functions of the ellipticity of a traveling light wave. It has been found that these parameters (amplitude, width, and amplitude-to-width ratio) depend strongly on the polarization of the light wave. In particular, the resonance amplitude can increase by more than an order of magnitude when the polarization changes from linear to optimal elliptic. It has been shown that this effect is associated with the Doppler frequency shift for atoms in a gas. The theoretical results have been corroborated in experiments in Rb vapor. 
D.V. Brazhnikov, A.V. Taichenachev, A.M. Tumaikin, V.I. Yudin, S.A.   Zibrov, Ya.O. Dudin, V.V. Vasil'ev, V.L. Velichansky