Resonance terahertz responses of one-periodic graphene strip grating embedded in a dielectric slab

The object of our study is the scattering and absorption of H-polarized plane wave of terahertz range by a flat grating of graphene strips embedded in a dielectric slab. In the H-case, the analysis uses the method of analytical regularization in the form of projection of the associated singular integral equation for the on-strip electric current to the set of Chebyshev polynomials, which invert the static part of the problem. In the E-case, the associated integral equation has only logarithmic singularity; we project it on the set of Legendre polynomials. As a result, in each case we obtain efficient numerical algorithm with guaranteed convergence. For arbitrary set of grating's parameters including the resonances, the accuracy of computations is controlled by the order of discretization. We study the dependences of the reflectance, transmittance, and absorbance by the graphene grating-in-slab scatterer on the strip width and frequency. We show that the strip width has effect only on the resonances on the surface-plasmon modes and does not influence the grating-mode and the slab-mode resonances in both polarizations.