Infrared Diffraction Radiation from Twin Dielectric Rods with Graphene Coatings as a Tool for Beam Position Sensing

This work presents a research into the infrared range diffraction radiation (DR) of a modulated beam of charged particles moving between twin dielectric circular nanowires covered with graphene. The latter are assumed zero-thickness and characterized with the Kubo formalism and resistive-type boundary conditions. We assume that the beam velocity is constant and apply the separation of variables in the local coordinates, combined with the addition theorem for the cylindrical functions. This enables us to cast the problem of DR to a Fredholm second-kind matrix equation and, therefore, guarantees the convergence. Due to convergence, both far and near DR-field characteristics can be computed with a controlled accuracy. The analysis shows the appearance of additional resonances linked with a deviation of the beam trajectory from the symmetric position. “Shining” of these resonances can be viewed as an instrument for the beam position monitoring with a nanoscale antenna.