Resonance scattering: Spectrum of quasi-eigenmodes of Two-Dimensional arbitrary open cavities

Complex resonances of open 2D arbitrary cavities are comprehensively investigated by the rigorous Method of Regularization. The quasi-eigenvalues for TM-modes are calculated with high accuracy for rectangular and elliptic cavities with longitudinal slot of various widths. In addition, these values are also calculated for one specially shaped duct-like structure. For cavities of rectangular and elliptic shape the effect of a slot location on the bounding contour is examined: the certain slot position dramatically impacts the existence of some TM-modes in the spectrum. Problems related to higher modes competition are also highlighted.