要約

The diffraction of a plane wave normally incident on a planar periodic structure with a square periodic cell of two slightly asymmetric complex-shaped metal elements has been numerically solved for the optical and infrared regions. The solution is due to the mapped pseudospectral Fourier method combined with the auxiliary differential equation technique and the pole model for describing the metal permittivity dispersion. It has been found that the structure can form a trapped-mode resonance outperforming in Q the plasmon-polariton resonances in structures with single metal element cells. It has been first shown that the high-order trapped-mode resonance can outperform in Q the corresponding fundamental trapped-mode resonance.