Guided modes in periodic planar system of metal cylinders

Guided modes in periodic systems consisting of silver cylinders are studied. Elementary cell in such systems comprise several identical guides. We employ multiple scattering formalism based on exact solution of Maxwell's equations for single waveguide problem. We also engage the technique that utilizes the transformation of sattice sums into fast convergent series. This method greatly increases the accuracy of calculations and sufficiently optimizes time cost of numerical simulations. It is shown that under the condition of nonzero propagetion constant these systems possess lcosely located guided modes. The number of these modes equals to the number of cylinders inside one elementary cell. The frequency of these modes decreases as quasi-wave vector runs over the Brillouin zone and approaches its edge. The modes are shifted towards high frequency region as propagation constant value increases thus allowing the modes to be found in near infrared or even visible part of the spectrum. It is also possible to simultaneously match the quasi-wave number and the frequency of dispersion curves in zigzag-shaped waveguide systems.