The improvement of lasing without inversion in the presence of multi-photon transition in a three-level atom confined in an optical cavity in the steady-state regime

Abstract

A three-level atom in \( \Lambda\) configuration trapped in a single-mode Fabry-Perot optical cavity is investigated. It is assumed that the transition between levels 2 and 3 in the atom is accomplished through the number of q photons. To solve the steady-state master equation for the atom-cavity system, the matrix continued-fraction method for applied physical quantities is used. The results show that by raising the number of transitions, the curves of the population inversion finally overlap with one another and the output mean photon number from the optical cavity rises and moreover the laser effect appears in the system. On the other hand, the outcomes reveal that by increasing the number of transitions despite the negativity of the population inversion, the number of output photons from the cavity grows and lasing interval becomes larger. Eventually the steps of the transformation from the three-level atom to two-level one in the case of multi-photon transition under several specific conditions have been studied. The obtained results of the simulations confirm the accuracy of the used approximations in the two-level pattern appropriately. In summary, the lasing process without population inversion along with the multi-photon transition in the three-level atom is discussed.