Cryogenic slab RF discharge CO laser with hybrid waveguide-unstable resonators

Dependences of a cryogenic slab radio-frequency discharge CO laser output power on a distance between mirrors of a hybrid negative-branch waveguide-unstable resonator were experimentally studied. The maximum output power was observed at the resonator length longer than the one calculated by taking into account the mirrors radii of curvature. Optimization of the resonator length made it possible to get the output power increase up to 20%–25%. The results obtained can be used for designing not only slab laser systems with hybrid waveguide-unstable resonators, but also for high-power lasers with full-sized negative-branch unstable ones.