Lasing from the upper vibrational levels of a flash-initiated H2–F2 laser

Abstract

Laser action has been observed from the P‐branch vibration‐rotation bands of the HF molecule from v = 6→5 to v = 1→0 transitions. In addition, the time‐resolved spectral behavior of this He‐diluted H₂–F₂ chain reaction chemical laser has been recorded. The HF* lasing molecules were produced by the reaction of a 50‐Torr gaseous mixture with mole ratio H₂/F₂/He=0.5/1/40 initiated by flash photolysis. In contrast to earlier results, strong lasing was found on the v = 6→5 and 5→4 transitions of the HF molecule. Within some of the bands from which lasing was observed, the time sequencing of transitions suggests non‐Boltzmann distributions of the rotational states.