Application RCWA for studying plasmon resonance under diffraction by metal gratings

A results of numerical analysis RCWA diffraction by metal gratings under plasmon resonance are presented. Numerical experiments show low convergence of traditional RCWA for such types of the resonances of electromagnetic field. Modified RCWA for studying resonance diffraction phenomena on metal gratings was proposed. Dielectric permittivity functional dependence of grating as complex Fourier series to improve convergence was presented.