Mode selection in laser resonators containing waveguide and open sections

Abstract

The folding resonator of the submillimeter molecular laser contains two circular metal waveguides. Homogeneous flat mirrors are located on one end of the waveguides. The opposite ends of the waveguides are optically connected by the system of the turning mirrors (STM). STM includes one flat and two spherical mirrors. For the purpose of the simplification of the task we shall consider the resonator has symmetry relative to reflection in a plane passing through a normal of a flat mirror of the STM.