assignement of the ammonia v2(2a->2s) rotational MIR laser transitions pumped by a tunable CO2 laser

In this work is reported the assignment of the NH3 MIR rotational laser lines previously observed inside the 2v2 vibrational level . Some of them are due the one-photon pump of the hot band 1s->2a, but the most part is assigned to off-resonance two-photon pumping ( 0a->1s->2a) induced at intermediate detunings as large as 600GHz.