  We study beam transmission and refection resulting from the resonant
excitation of forward and backward surface waves in a metamaterial. We predict
that exciting these waves at an interface this medium and free space led to
transmitted and reflected beams with high amplitudes. The FDTD simulated
results demonstrate clearly propagation of these waves and their
energy-trapping ability as described by theory. The resonant coupling of the
refracted waves and reflected waves at the first interface led to the
excitation of the backward surface waves. The forward surface waves transfer
incoming energy in the direction of incidence and the backward surface transfer
incoming energy in a direction opposite to the direction of incidence (i.e.
negative direction). More also, the parameters used in these simulations were
carefully chosen to minimize the effects of interference between the incident
and the reflected beams earlier reported. In overall, these numerically
simulated results clearly demonstrate the propagation of these waves and may
serve as numerical approximations to what might be observed in experimental
setups. Putting this simply, they may find applications in optical and photonic
devices involving enhancing beam transmission and reflection using
negative-index metamaterial.
