  The fundamental guided dispersion characteristics of guided light in a
subwavelength dielectric slit channel embedded by two different plasmonic
metals are investigated when varying the gap width. As a result, an overall and
salient picture of the guided dispersion characteristics is obtained over a
wide spectrum range below and above the plasma frequencies of the two different
plasmonic metals, which is important preliminary information for analyzing this
type of subwavelength waveguide. In particular, the effects of using two
different metals on the guided mode dispersions are emphasized in comparison
with the effects of using the same plasmonic metal cladding.
