Waveguide higher mode pumping through a dielectric resonator

Abstract

Waveguides are usually not used at frequencies close to or above the second critical frequency, due to a transition to multimode regime and dispersion losses. Our paper shows how this obstacle can be overcome in a non-destructive way by inserting a dielectric resonator. Here, we consider a model consisting of a bent waveguide section that generates higher-order harmonics and a compensating cylindric resonator. We examine both symmetric and asymmetric compensation methods for higher-order modes by modifying the resonator arrangement. The obtained results make it possible to modify information and telecommunication and measurement systems in such a way as to directly pump energy into one of the higher modes, ignoring the rest. Thus, even waveguide systems designed for low frequencies can be used higher frequencies, simplifying the measurement of highly anisotropic substances and large samples.