Ensemble of asymmetric quantum dots in a cavity as a terahertz laser source

The possibility of establishing a terahertz laser generation at a transition between the dressed states formed by the interaction of an intense optical field with an ensemble of asymmetric quantum dots (QDs) in a high-$Q$ terahertz cavity is discussed. It has been shown that the population inversion in the system of dressed states is achieved owing to spontaneous relaxation of the excited state of the QDs. The set of Maxwell–Bloch equations for the difference between dressed-state populations, polarization, and population of the cavity mode has been analyzed in the mean-field approximation. The lasing conditions have been clarified and the possibility of controlling the terahertz radiation intensity has been studied, including the case of an inhomogeneously broadened ensemble of QDs.