Direct measurement of plasmon propagation length of Ag nanowire waveguide via polymer nanofiber launching

Abstract Herein, we demonstrate a simple, direct measurement of plasmon propagation length of Ag nanowire waveguide. Using dye-doped polymer nanofiber for launching, propagating surface plasmon polaritons on multiple silver nanowires are efficiently excited under wide-field illumination. By monitoring the length dependence of the intensity of scattering light at the nanowire ends, a typical plasmon propagation length of 15.1 ± 1 . 0 μ m in Ag nanowire with 120 nm in diameter is directly extracted. Photon–plasmon coupling efficiency of about 40% is determined, which is independent of the orientation of Ag nanowire.