Continuous-wave terahertz waveguide lasers

THz lasers with optical pumping (THz OPL) are successfully used in the diagnostics of high-temperature plasma, magneto-polarimetry and spectroscopy of semiconductors, measurement of the parameters of polymeric materials, medicine and biology. Open and waveguide resonators are an effective means of rarefaction of the spectrum, which made it possible to achieve well-known successes in laser technology. For many scientific and applied applications, a given form of the transverse spatial distribution of the output beam field is required, different from the Gaussian mode distributions of quasi-optical open resonators. In this work, various issues related to THz OPL are considered ¿ the basic principles of their operation, features of resonant systems, construction principles and design features of small-sized THz OPL. A THz OPL with a quasi-uniform output beam profile was proposed and experimentally investigated, based on a combined waveguide quasi-optical resonator of folded construction. The possibilities of using a quasi-optical waveguide resonator with various transverse mode selectors to create compact wide-range THz OPLs are studied.