Properties of One-Dimensional Metal Gratings at Inclined Incidence of Terahertz Radiation

Metal gratings formed by parallel conductors are widely used as elements of various devices in the terahertz (THz) frequency range. With a change in the angle of incidence of radiation on the grating, the reflection and transmission coefficients of this grating change. Moreover, with certain grating parameters, the nature of the change in the reflection and transmission coefficients can differ significantly from the linear dependence. Especially when the period is comparable to the wavelength. Theoretical models for calculating grating parameters exist and used. However, in real gratings there are a number of design and technological features, the influence of which is theoretically extremely difficult to take into account. Therefore, along with theoretical calculations, comparative measurements are required. This is especially true in the THz range, where there is a shortage of experimental data. The aim of the work is the experimental determination of the properties of one-dimensional metal gratings at different angles of incidence of a plane electromagnetic wave in them in the THz range. An experimental determination was carried out of the propagation of laser radiation with a wavelength of 337 μm through wire gratings with a pitch of 400 and 200 μm at various incidence angles of THz radiation. The analysis of the experimental data and their comparison with theoretical calculations obtained. The experimental results correlate with theoretical data and most fully characterize the properties of the gratings, taking into account their design and technological features. Which are extremely difficult to consider in theoretical calculations. The resonance maxima in the dependences of the transmitted radiation power on its angle of incidence practically coincide with the calculated data. This makes possible to develop a number of measurement methods. The recommendations have been developed to improve the accuracy of measurements and the practical use of the obtained data. The obtained experimental results contribute to the study of the electrodynamic properties of one-dimensional metal gratings in the THz range.