  We experimentally demonstrate the propagation of long-range surface
plasmon-polaritons in a nobel metal stripe waveguide at an optical wavelength
of 780 nm. To minimize propagation damping the lithographically structured
waveguide is produced from a thin gold stripe embedded in a dielectric polymer.
Our waveguide geometry supports a symmetric fundamental and anti-symmetric
first order mode. For the fundamental mode we measure a propagation loss of
$(6.12^{+0.66} _{-0.54})$ dB/mm, in good agreement with numerical simulations
using a vectorial eigenmode solver. Our results are a promising starting point
for coupling fluorescence of individual solid state quantum emitters to
integrated plasmonic waveguide structures.
