  Chemical synthesized silver nanowires have been proved to be the efficient
architecture for Plasmonic waveguides, but the high propagation loss prevents
their widely applications. Here, we demonstrate that the propagation distance
of the plasmons along the Ag NW can be extended if the Ag NW was placed on a
dielectric multilayer substrate containing a photonic band gap, but not placed
on a commonly used glass substrate. The propagation distance at 630 nm
wavelength can reach 16 um even that the Ag NW is as thin as 90 nm in diameter.
Experimental and simulation results further show that the polarization of this
propagating plasmon mode was nearly parallel to the surface of the dielectric
multilayer, so it was excited by a transverse-electric polarized Bloch surface
wave propagating along a polymer nanowire with diameter at only about 170 nm on
the same dielectric multilayer. Numerical simulations were also carried out and
consistent with the experiment results. Our work provides a platform to extend
the propagation distance of plasmonic waveguide and also for the integration
between photonic and plasmonic waveguides on the nanometre scale.
