Re-investigation of optically pumped hydrazine far-infrared laser around 11 μm from the 10HP and 10P bands of a pulsed CO2 laser: new lines and assignments

A high-peak-power (several hundreds of watts) pulsed CO₂ laser, recently developed in our laboratory, has been used for exciting optically pumped far-infrared laser transitions of N₂H₄. A systematic search for N₂H₄ absorption coincidences with 10P and 10HP CO₂ laser emissions has led to the observation of 27 new far-infrared laser lines, excited by 18 different absorption transitions. All of these new lines have been characterized in wavelength, offset, relative polarization, optimum operation pressure and intensity. Using the LaseRitz program, ten of these lines were assigned, corresponding to five laser systems. For other two laser systems possible J and K quantum numbers of the energy levels involved in the laser transitions were given.