Perturbative solution for analysis of coherent processes in a double-Λ atomic scheme

Typically, a numerical solution of OBEs is used in the theoretical treatment of atomic system of two Λ schemes. In this work, interactions of four laser fields driving a DΛ level scheme were analyzed by using perturbative method to solve OBEs Dimitrijević et al. (2011) [7]. Perturbative method produces simpler solutions such that analytical expressions can be obtained. The comparison of results obtained using lower-order corrections of perturbative method, and the exact calculations using optical Bloch equations is presented. Analytical expressions provide valuable information about processes that occur in the DΛ atomic system. These informations cannot be deduced from the numerical solutions of the OBEs for the same atomic scheme.