A Quantum Optical Approach to the effect of a Laser Mode on the Motion of Atomic Vapor by Varying the Field Coherence Angles

Abstract

We follow theoretically the motion of the sodium atoms in vapor state under the influence of a laser mode in (1 + 1) D, which is achieved by introducing different optical filters. In the Dirac interaction representation, the equations of motion are represented via the Bloch form together with the Pauli operators to find the elements of the density matrix of the system. The emergence of the principle of coherence in varying the angles of the laser mode permits the evaluation of the average force affecting the atoms' acceleration or deceleration, and hence the corresponding velocities and temperatures are investigated. The atomic vapor is introduced in a region occupied by a heat bath presented by the laser field, such that the state of the atomic vapor is unstable inside the system due to the loss or gain of its kinetic energy to or from the laser field. This instability is studied by finding the eigenvalues of the system's entropy. Resorting to the assumption of Botin, Kazantsev, and Pusep, who issued in the presence of the weak and strong spontaneous emission, a coupling between the mean numbers of photons in terms of time, which allows the evaluation of the rate of entropy production of the system under study. No singularities are found throughout the process of equations solving and other calculations. Resorting to symbolic software, a set of figures illustrating the nonlinear behavior in the dynamics of the problem is present. In this paper, we introduce a theoretical study of the effect of two-counter propagation traveling plane waves on the motion of the sodium atoms in the vapor state by varying the coherence angles to investigate the atomic behavior. Good agreements are found with previous studies.