Optical properties of pulsed generation in capillary gas lasers with internal-mirror waveguide resonators

The angular distribution and coherence of pulsed capillary lasers with the optical feedback implemented by waveguide Fabry-Perot resonators with internal mirrors have been theoretically studied. We have shown that spatially-coherent, low divergence radiation can be generated even for short pulse duration if the cavity parameters (the refractive index of the capillary wall and the waveguide dimensions) are properly chosen.