Two-dimensional periodic structures: Investigation, application and methods for solving problems of diffraction of electromagnetic waves

Periodic structures are widely used in different areas of science and technology, forming the grounds for various types of devices [1]. In the microwave range diffraction gratings are used as polarizers, frequency-selective surfaces, quasi-optical beam splitters, protective masking materials that are transparent to electromagnetic waves. Periodic structures are slow-wave structures in electronic devices and in accelerators. An optical grating is the main element of spectrometers.