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 O2 laser. For each line we report all the available data on the CO2 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 CO2 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 N2H4 absorption spectrum. We can confirm the assignments for only 37 FIR laser lines belonging to 20 laser systems.
© 2005 Optical Society of America
Andrea De Michele, Giorgio Carelli, Giovanni Moruzzi, and Augusto Moretti, "Hydrazine far-infrared laser lines and assignments: a review," J. Opt. Soc. Am. B 22, 1461-1470 (2005)