Exact simulation method for analysis of open resonators with step-like deformation of mirrors

Several effective methods of analysis of quasi-optical open resonators (ORs) with smooth mirrors exist. The analysis of the OR with the diffraction grating is a more challenging task, because the grating is an additional dispersive element in the OR and has a inhomogeneous surface. There are many such ORs of a complicate configuration, where the inhomogeneous mirrors can be conceived as a step-like regular surface. An efficient rigorous solution of the excitation problem of the complicated OR is presented in this report. As an example, the spectrum and the mode field topology of the corner-echelette OR are calculated and several results are shown