Open resonator with trapezoidal mirror for terahertz DRO

For the two-dimensional open resonator (OR) with a trapezoidal mirror and a flat mirror covered with a reflective diffraction grating, the examinations of a spectrum and Q-factor of excited modes are carried out. The advantages of the trapezoidal mirror are shown in comparison with a spherical mirror for shaping an extended interaction space in terahertz (THz) frequency range. The outcomes of scale experiment in 10-mm waveband of mode selection in OR are presented.