Hydrazine far-infrared laser lines and assignments: a review (original) (raw)

The hydrazine molecule is one of the most prolific far-infrared (FIR) laser sources. We present a complete list of its 268 observed FIR laser emissions excited by the 12 C 16 O 2 laser. For each line we report all the available data on the CO 2 pump line, the frequency measurement when available, the wavelength, the optimum operating pressure, the relative intensity, the polarization relative to the pump radiation, and the absorption offset from the CO 2 line center. In spite of the large amount of experimental research performed on the hydrazine laser, only a few papers have reported the assignments of the levels involved in the laser systems. In fact, a systematic assignment of the IR hydrazine absorption spectrum is only at a preliminary stage owing to the complexity of the Hamiltonian of this molecule. We have investigated the possible assignments for all the reviewed FIR laser emissions by comparison with an N 2 H 4 absorption spectrum. We can confirm the assignments for only 37 FIR laser lines belonging to 20 laser systems.