Independently analyzing different surface plasmon polariton modes on silver nanowire.

In this paper, surface plasmon polariton (SPP) modes on silver nanowire (AgNW), with different field symmetric, are studied by different near field methods, respectively. In the experiment, the excitation and detection of SPPs are performed by two probes of near field scanning optical microscope (NSOM) simultaneously, which realizes the study of SPPs in complete near field. By controlling the experimental conditions, two of the fundamental SPP modes are detected separately and their intensity distributions on AgNW are given by the NSOM images. In the discussion, creeping wave (CW) is introduced to analyze the experimental results, which improves the coincidence of the experimental results and the theoretical calculations. A detailed characterization of SPPs modes in near field, which gives a further insight into optical properties of AgNW, will benefit integrated optical circuits.