An investigation of a chemical laser emitting due to an overtone of the HF molecule

The emission wavelength of a chemical HF laser was shortened by the use of molecular overtones as the active transitions in initiation of chemical reactions in SF₆–H₂S (HBr)–He mixtures by longitudinal electric discharges. The efficiency of conversion of the chemical energy into coherent radiation at the overtone frequency was ~15% of the fundamental frequency. The output radiation intensity, 10³ W/cm², was sufficient for the use of this laser as an overtone master oscillator in conjunction with an amplifier based on the H₂–F₂ chain reaction.