The absorption modes of a dielectric-metal-dielectric nanorod array in the Kretschmann configuration

The glancing angle deposition (GLAD) technique is applied to fabricate a three-layered dielectric-metal-dielectric anisotropic thin film. The silver nanorod array is between two SiO2 nanorod arrays (NRA). The three-layered thin film is arranged in the Kretschmann configuration and measured the reflectance of the system. The polarization conversion reflectance is measured from this system as the plane of incidence is not coincident with the deposition plane. From the angular spectra of reflectance for RPP, RSS, RSP and RPS (Rij, i denotes the polarization of the incident beam and j denotes the polarization of the reflected light) measured at angles larger than critical angle, the absorption for s-polarization and p-polarization incident light can be calculated. The resonant peaks varied with the orientation of the deposition plane are also measured. The configuration combines polarization conversion, transverse surface plasmon resonance and longitudinal surface plasmon resonance of the rods. Those resonances are associated with the relationship between the rod directions and the oscillating electric field vector. The variations of the absorption peaks affected by those resonant modes are discussed in this work.