Continuous flow combustion lasers - A review

The paper reviews the operating principles, the development, and the present state of two major classes of continuous flow combustion driven lasers - gas dynamic lasers (GDL) and chemical mixing laser (CML). In these devices, gas-phase combustion reactions continuously pump high-power infrared laser emission on vibrational-rotational transitions of molecular species formed by exothermic combustion reactions. In GDL devices, pumping of the laser emission proceeds through thermal equilibrium followed by sudden aerodynamic expansion to yield vibrational-state population inversions. In CML devices, pumping proceeds through direct generation of population inversions among vibrational states in the product molecules of nonequilibrium gas-phase elementary exothermic chemical reactions. A description of key kinetic processes and operant mechanisms in CML devices is given.