Transmission properties and band structure of a segmented dielectric waveguide for the terahertz range

In this paper we investigate the band structure of guided modes in a segmented planar waveguide for the terahertz range. The dispersion curves are obtained using two different methods. The first approach is based on a close relationship between the band structure and narrow resonances in transmission spectra: transmission spectra are therefore calculated using a transfer matrix method and compared to the experimental ones. The second technique involves a modal analysis approach of diffraction gratings and it is used for direct calculation of the band structure. Propagation of THz guided waves along the grating considered as a segmented dielectric waveguide is also investigated using a bi-directional mode expansion and propagation method. All approaches are compared to each other and discussed.