  We theoretically and numerically investigate the phenomenon of resonant field
enhancement of Gaussian beams in two types of transition metamaterials: with a
positive-zero-negative index profile and with a positive-zero-positive index
profile and demonstrate strongly localized resonant field enhancement in both
cases. This study is likely to have applications in the fields of nano-optics,
sub-wavelength imaging, and nano-fabrication and lays a foundation for the
studies of more complex vector and vortex beam propagation in graded-index
metamaterials.
