posted on 2020-03-16, 16:11authored byShuichi Toyouchi, Mathias Wolf, Yusuke Nakao, Yasuhiko Fujita, Tomoko Inose, Beatrice Fortuni, Kenji Hirai, Johan Hofkens, Steven De Feyter, James Hutchison, Hiroshi Uji-i
Silver
nanowires have attracted considerable attention as subdiffraction
limited diameter waveguides in a variety of applications including
cell endoscopy and photonic integrated circuitry. Optical signal transport
occurs by coupling light into propagating surface plasmons, which
scatter back into light further along the wire. However, these interconversions
only occur efficiently at wire ends, or at defects along the wire,
which are not controlled during synthesis. Here, we overcome this
limitation, demonstrating the visible laser light-induced fabrication
of gold nanostructures at desired positions on silver nanowires, and
their utility as efficient in/out coupling points for light. The gold
nanostructures grow via plasmon-induced reduction of Au(III) and are
shown to be excellent “hotspots” for surface-enhanced
Raman scattering.