Configuration and key features of quasi-optical open resonator with step-like deformation of mirror

The dispersive properties of an open resonator (OR) with a smooth mirror are inadequate for some practical problems. The application of a diffraction grating as a reflector of the OR is a classical way of spectrum rarefaction, but in so doing the analysis of the the OR excitation becomes more complicated. It is possible to reduce the problem of analysis, when it is considered that the diffracted grating may be represented as a surface having periodical step-like deformations. The second aspect of the problem discussed is concerned with the search for a new way to control an OR spectrum. In as much as an oscillation process in an OR is attended by radiation into free space, it should be expected that the OR spectrum is determined by wave diffraction at the mirror boundary. By varying the diffraction conditions at the borders of the mirror we can realize control over the mode excitation and thereby control the key characteristics of the OR.