Semi-implicit FDTD TW scheme for modelling effective surface plasmons

摘要： A semi-implicit finite-difference time-domain thin-wire (TW) scheme with a relaxed stability condition is proposed for modelling effective surface plasmons in waveguide metamaterials. Its formulation is based on introducing the Newmark-Beta method into the TW formulation based on the contour-path integral of Maxwell’s equations around a wire. The resultant scheme is magnetically implicit. Its stability, accuracy and efficiency are assessed in the application to a wire-added parallel-plate waveguide perturbed with a small gap.