Quantum-stohastic equation for radiation-balanced laser

A quantum-mechanical description of quasi-two-level solid-state laser is presented. The impurity ion levels are coupled both by the phonons of the host lattice and by the radiation field. The set of dynamic Heisenberg–Langevin equations for the material system and the phonon operators has been derived. These equations include radiative and nonradiative damping terms and quantum-stohastic forces. This description could be used for investigation of the influence of phonon dynamics on a radiation-balanced laser stability.