Dubinin M. Formation, diagnostics and control of the radiation of focused terahertz laser beams

The thesis is devoted to theoretical and experimental studies of the physical laws of the formation, focusing of wave laser beams of continuous terahertz radiation with inhomogeneous spatial polarization and control of the radiation of focused laser beams. To solve these problems, the methods of modern radio physics, computational electrodynamics and mathematical physics were used. The methods and schemes of formation and selection of transverse modes with different spatial polarization of the field in waveguide quasi-optical resonators proposed and studied in the dissertation can be used in the development and creation of new designs of laser systems with controlled characteristics for scientific and applied research - single-mode lasers with a given shape and polarization of the initial beam. The results of laser beam focusing studies can be used to solve problems related to the interaction of electromagnetic waves with matter: diagnostics of the surface of materials, thin films, biological objects, achieving subwavelength resolution of THz tomography, for radar and telecommunications applications, etc. The proposed method of controlling tightly focused laser beams can be applied in such applications as obtaining terahertz images (including extended objects), laser ablation, and optical discharge generation, where focusing of terahertz radiation with an increased depth of focus is necessary.