Abstract
In this paper, we investigate a system Hamiltonian describing the interaction between SU(1,1) quantum system and a three-level atom in Λ configuration in presence of a classical external field. Appropriate conical transformations are performed for the atom matrices. The analytical solution of the model is obtained by using the Schrödinger equation. Then the atomic density operator of the proposed system is obtained. The effect of the detuning parameter and the classical external field on the atomic levels occupation, atomic entropy squeezing, variance squeezing, atomic Q-function and atomic Wehrl density are investigated for certain chosen values of the classical field parameter and the detuning parameter. The obtained results has a potential applications to topics related to ideal and real laser.