Integral equation modeling of the THz wave scattering by graphene-strip gratings

The plane wave scattering and absorption by finite and infinite gratings of free-space standing graphene strips are studied in the THz range. Both finite and infinite gratings are studied. The formulation involves modified boundary conditions imposed on the strips. We build an accurate numerical solution to this problem based on the hyper-singular integral equations and the Nystrom method of their discretization. This guarantees fast convergence and controlled accuracy of computations. Reflectance, transmittance, and absorbance as a function of the wavelength and the grating parameters are analyzed, revealing surface-plasmon resonances and gradual build-up of Rayleigh anomalies if the number of strips gets larger than a few dozens.