Planar chiral irises in a square waveguide and "optical activity" manifestations

A square waveguide with a four-slot iris possessing four-fold symmetry of rotation and complementary simple elements is addressed to analyze the spatial spectrum of modes exited in the reflected and transmitted fields. The cross-polarized field was identified behind the waveguide object. The reasons for its appearance, revealed and examined, enable the obtained conclusions to be extended to the "optically active" metamaterials built around periodically arranged planar chiral elements.