  We present here the transmission of electromagnetic waves through layered
structures of metallic and left-handed media. Based on the theory of finite
periodic systems, we show that besides the strong influence of the incidence
angle, the low transmission characteristic of a single conductor slab, for
frequencies $\omega$ below the plasma frequency $\omega_p$, becomes in this
domain highly oscillating. Similarly, the well-established transmission
coefficient of a single left-handed slab becomes highly resonant with
superluminal effects in superlattices with more than one unit cell. We
determine the space-time evolution of a wave packet through the $\lambda/4$
photonic superlattice whose transmission coefficient is a sequence of isolated
and equidistant peaks with negative phase times. We show that the space-time
evolution of a Gaussian wave packet, with centroid at any of these peaks,
agrees with the theoretical predictions, and no violation of the causality
principle occurs.
  We show that besides the strong influence of the incidence angle, the
coherent coupling of the bulk plasmon modes and the interface surface plasmon
polaritons lead to oscillating transmission coefficients, and depending on the
parity of the number of unit cells $n$ of the superlattice, the transmission
vanishes or amplifies as the conductor width increases. We determine the
space-time evolution of a wave packet through the $\lambda/4$ photonic
superlattice whose bandwidth becomes negligible, and the transmission
coefficient becomes a sequence of isolated and equidistant peaks with negative
phase times. We show that the space-time evolution of a Gaussian wave packet,
with the centroid at any of these peaks, agrees with the theoretical
predictions, and no violation of the causality principle occurs.
