Radiation induced gas-dynamic refractive index changes in an iodine laser oscillator

Due to the exothermic recombination of ground state iodine atoms I with free radicals C₃F₇ to the parent molecule C ₃F₇I, the gaseous medium of an iodine laser oscillator is subject to spatially inhomogeneous heating. This causes temperature and pressure gradients leading to gas-dynamic motion and thus to density and refractive index changes perturbing the optical quality of the laser medium. Since the strength of the recombination reaction depends directly on the laser intensity via the process of stimulated emission, this coupling can lead to self-termination of the laser radiation. This phenomenon is experimentally and theoretically investigated