Absorption And Dispersion Spectrum Of Cascade Three-level Atom In Single-Mode Cavity Field

The absorption and dispersion of light are the basic properties of optical media and an important subject in the study of quantum optics,nonlinear optics and the interaction between light and atoms.In particular,the new phenomena of interest,such as electromagnetically induced transparency,coherent layout capture,and so on,are based on the atomic coherence effect,that is,the interaction between light and atoms leads to changes in the absorption and dispersion of light in optical media.Therefore,it is of great significance to study the absorption and dispersion of light in optical media.In this paper,the absorption and dispersion properties of cascaded three-level atoms in a single-mode cavity driven by a classical field are studied and the cavity field is coupled with a transition of a cascade three-level atom.Under the theory of dressed state,using the master equation,the Langevin equation is acquired.Using the quantum regression method to calculate the polarizability.The real part of the polarizability is dispersion,and the other is absorption.The results show that,firstly,absorption dispersion spectrum of two-level atoms in a single-mode cavity presents two-peak structure,and there are four peaks in the case of three-level atoms.Sec-ondly,Absorption dispersion spectrum of cascaded three-level atoms in a single-mode cavity driven by a classical field narrows,but this phenomenon is not found in the cascaded three-level without the cavity.And we also find the narrowing absorption dispersion spectrum in the non-cavity coupling transition.That meas the case of cav-ity field coupled transition channel has certain influence on the absorption dispersion spectrum of no cavity coupled transition.