Electromagnetically induced absorption and transparency in magneto-optical resonances in elliptically polarized field

摘要

Using a 1 to 2 transition as an analytically tractable model, we discuss indetail magneto-optical resonances of both EIA (electromagnetically inducedabsorption) and EIT (electromagnetically induced transparency) types in theHanle configuration. The analysis is made for arbitrary rate of depolarizingcollisions in the excited state and arbitrary elliptical field polarization.The obtained results clearly show that the main reason for the EIA sub-naturalresonance is the spontaneous transfer of anisotropy from the excited level tothe ground one. In the EIA case we predict the negative structures in theabsortpion resonance at large field detuning. The role of the finite atom-lightinteraction time is briefly discussed. In addition we study non-trivialpeculiarities of the resonance lineshape related to the velocity spread in agas.