Propagation and focusing of modes of the dielectric resonator of terahertz laser

Theoretically on the basis of the vectorial Rayleigh-Sommerfeld theory and experimentally using terahertz radiation of the waveguide laser (λ = 0.4326 mm) the physical features of propagation and “moderate” or “sharp” focusing of laser beams of radiation are investigated in free space which described by modes of circular hollow dielectric waveguide with different spatial polarization.