A laser may comprise a ceramic body including a first wall and a second wall opposite the first wall, a first mirror positioned at first ends of the first and second walls, a second mirror positioned at second ends of the first and second walls opposite the first ends, the first and second walls and the first and second mirrors defining a slab laser cavity within the ceramic body. The laser may further comprise a first electrode positioned outside the laser cavity and adjacent to the first wall of the ceramic body and a second electrode positioned outside the laser cavity and adjacent to the second wall of the ceramic body, wherein a laser gas disposed in the laser cavity is excited when an excitation signal is applied to the first and second electrodes. In some embodiments, the first and second mirrors may form a free-space multi-folded resonator in the slab laser cavity. In other embodiments, the first and second mirrors may form a free-space unstable resonator in the slab laser cavity. In still other embodiments, the first and second mirrors may form a waveguide unstable resonator in the slab laser cavity.