Electromagnetic waves propagating in a periodic array of parallel metallic carbon nanotubes

This is a theoretical study of electromagnetic modes, guided by infinitely long single-wall metallic carbon nanotubes, forming two-dimensional periodic array. It demonstrates that electromagnetic coupling dramatically raises the slow-wave factor of modes propagating in arrays compared to that observed in single carbon nanotubes. It is found a strong dependence of the slow-wave factor on a wave vector of the Floquet-Bloch wave k_⊥ (the transversal wave vector) propagating in the plane of periodicity. The slow-wave factor varies from unity as |k_⊥|→0 to more than two hundreds for high values k_⊥. Considerably low attenuation at terahertz frequencies is demonstrated. Comparison of electromagnetic properties of arrays of metallic carbon nanotubes and conventional wire media is discussed. Transmission of a plane wave through a finite-thickness slab, which can be used as a terahertz polarizer, is analyzed.