Senyuta V. Formation modes with spatially-inhomogeneous polarization in the waveguide resonators of terahertz range.

The dissertation is devoted to study of the regularities of the intracavity formation of the laser beams with an inhomogeneous spatial polarization in the terahertz range. The conditions of applicability of the method of the natural oscillations for solving modeling of the propagation of terahertz radiation in the oversized metal waveguides in the model of “ideal conductivity of the metal” and the model of “dielectric with absorption and frequency dispersion”, depending on the wavelength of the laser radiation in the frequency range 4 - 28 THz are founded.I The method for generation of a single transverse mode with the azimuthal polarization of the field in an optically pumped terahertz band laser is suggested.The physical features of free-space propagation for radiation beams by excited modes of terahertz laser based on a hollow circular waveguide with different spatial polarization field are investigated theoretically and experimentally. The stable structure of the field for studied modes in the terahertz range is observed at shorter distances from the end of the waveguide in comparison with the distances predicted by the criterion for the far-field diffraction.