Propagation and Focusing of Low-order Modes of a CW THz Waveguide Laser

Wave beams with different spatial polarizations have found a variety of practical applications. These beams are used in material processing, high resolution metrology, electron acceleration, spectroscopy and microellipsometry. However, at the moment, there are practically no theoretical or experimental results on the features of propagation and focusing of CW THz radiation. For a theoretical study of the propagation and focusing of THz laser beams excited by the modes of a waveguide quasi-optical resonator, the Rayleigh-Sommerfeld vector theory was applied in the work. Well - known methods of measuring in the THz range were used for experimental study. The obtained results supplement the ideas about the features of the propagation of terahertz laser beams, as well as their sharp and moderate focusing.