Levels width in triple-barrier structures in two-photon transitions

For asymmetric triple-barrier resonant-tunneling structures with thin high barriers, the simple expressions describing resonant transitions in the large-signal high-frequency electric fields have been obtained taking into account levels width. It is shown that conditions exist for every structure, when the majority of electrons falling on the upper energy level can emit two photons and then leave the structure without any intermediate interaction. The number of regions without reflection can reach four.