Long-Period Gratings Based on Surface Plasmon Polariton Waveguides in Fluorinated Polymer

This letter presents devices composed of long-period gratings and long-range surface plasmon polariton waveguides. The waveguide is formed by embedding a thin Au stripe in a low optical absorption perfluorocyclobutane polymer. The grating structure is created on a corrugated silica substrate and then transferred to the polymer layer, producing a periodic modulation of refractive index along the waveguide. Strong grating resonances are observed. The coupling mechanism and the device thermal dependence are examined.