Modes focusing of metal resonator of terahertz laser

Abstract

Theoretically, based on the Rayleigh-Sommerfeld vector theory using the radiation of a waveguide terahertz laser (0.4326 mm), the physical features of the moderate and sharp focusing of radiation beams excited by the modes of a laser cavity based on a circular metal waveguide for various spatial polarization of the field were studied. It is shown that in the focal region of the lens, in the case of sharp focusing of the radiation beam excited by the radially polarized TM01q mode, a significant increase in its axial intensity is observed, due to a significant increase in the intensity of the longitudinal component of the field of this mode in this case. The obtained results broaden the knowledge of the focusing features of the laser beams of the terahertz range.