Near-field optical imaging of periodic plasmon sources

Summary form only given. Progress in scanning near-field optical microscopy has opened an opportunity to study two-dimensional optics of surface plasmon waves, which is essential for such applications as integrated plasmon sensor fabrication. We report on the design and near-field imaging of a novel periodic array of surface plasmon sources. This array has been fabricated by cutting and polishing an output face of a fiber bundle which has a 3 /spl mu/m spacing between individual fiber cores, followed by deposition of a 100 nm thick silver film on the polished face. The cutting angle corresponds to the phase-matched excitation of surface plasmon waves on the silver film surface by light exiting the cores of the fibers in the bundle. Transmission spectrum of the structure exhibits clear indication of two-dimensional photonic crystal behavior, caused by the periodic refractive index variations of the substrate.