In this paper, we have investigated some parameters of a radio frequency (RF) excited diffusively cooled all-metal slab waveguide CO2 laser based on the modified Rigrod theory by introducing a waveguide coupling efficiency which designates the coupling between the waveguide and the resonator mirrors. The parameters of the laser small signal gain g0, saturation intensity Is, and waveguide coupling efficiency (\eta) are studied theoretically and experimentally. In the experiments, three sets of ou
