Enhanced THz transmission through a grating with layered high-temperature superconductor
J. G. Medrano1, S. Cortés-López2, and F. Pérez-Rodríguez1
1Instituto de Física, Benemérita Universidad Autónoma de Puebla, Apdo. Post. J-48, Puebla, Pue., 72570, México
2Departamento de Investigación en Física, Universidad de Sonora, Apdo. Post. 5-088, Hermosillo, Sonora 83000, México
Received March 2, 2021, published online June 25, 2021
The diffraction of terahertz (THz) electromagnetic waves by a grating, composed of alternating layered high-temperature-superconductor bars and dielectric ones, is theoretically studied. The formalism of the finite Fourier transform is applied for calculating the relative intensities of the diffracted THz waves. Assuming that the superconducting layers and the electric field of the incident electromagnetic wave are parallel to the axes of the grating bars, it is found that the intensity T0 of the zero-order diffracted waves into the substrate vanishes at low frequencies even at very small superconductor filling fractions. However, at frequencies just below the lowest cutoff frequency, the transmissivity T0 turns out to be considerably enhanced and its relatively large value is maintained at higher frequencies.