Lasing regimes and emission characteristics of a ring iodine photodissociation laser

An experimental investigation was made of the energy, space-time, and polarization characteristics of an atomic iodine photodissociation laser with a four-mirror ring resonator. The direction of lasing was governed mainly by weak reverse signals which could originate, in the absence of auxiliary mirrors, from parasitic reflections or scattering. Under flashlamp pumping, an influence of dynamic inhomogeneity waves on the lasing threshold was manifested in the space-time structure of the near-field pattern. It was established that the polarization of the emitted radiation was linear in the absence of external magnetic fields. It was shown that one can use a ring-laser oscillator for investigations on amplifying systems, and that this approach ensures suppression of amplifier self-excitation by reflection from the resonator mirrors.