Аннотация
The theoretical analysis of the open electrodynamic system, which is a symbiosis of an open resonator and a segment of a rectangular waveguide, is carried out in the work. It is shown that the transverse dimensions of the waveguide made at the center of one of the mirrors of the open resonator are uniquely determined by the geometric parameters of the resonator and the working wavelength. In this case, the maximum efficiency of excitation of the main wave ТЕ10 in a rectangular waveguide with the help of the fundamental oscillation of the open resonator ТЕМ00q is 88%. As it turned out, in this case the normalized transverse dimensions of the waveguide are oversized, and the considered system can be used to measure the ultra-weak luminescence of seeds of grain crops.