Dispersion characteristics of terahertz photonic crystal waveguide

A new type of terahertz (THz) photonic crystal waveguide is proposed and its dispersion characteristics are investigated. The cladding of this THz photonic crystal waveguide is silicon material containing periodic circular air holes arranged as triangular lattice, and the material of its core is polythene (PE). The band-gap distribution is studied by plane wave method (PWM), absorption boundary is determined by perfectly matched layer (PML), and dispersion characteristics are analyzed by finite-difference time-domain method (FDTD). Results show that waveguide dispersion is strongly affected by structure parameters, e.g. air hole diameter, spacing between air holes and core radius. The value, slope and zero-dispersion point of waveguide dispersion can be adjusted by changing structure parameters. Better dispersion characteristics could be achieved at higher air-filling factor.