Fig. 1. Schematic of the Ag nanostructures. (a) Cylindrical Ag nanostructures; (b) xz view of simulation model in FDTD Solution

Fig. 2. (a) Extinction spectra of Ag nanostructures with different diameters; (b) variation trend of the resonance position and the resonance intensity with diameter; electric field distributions of 160 nm cylindrical nanostructures on the xz plane at (c) 383 nm and (d) 579 nm

Fig. 3. Electric field distributions at the interface for Ag nanostructures with diameters of 40, 60, 80, and 120 nm

Fig. 4. (a) Electron distributions of longitudinal mode and transverse mode of Ag nanostructures; (b) extinction spectra of Ag nanostructures with different heights; (c) variation of the resonance position and the resonance intensity with height

Fig. 5. (a) Extinction spectra of Ag nanostructures with different spacings; (b) variation of the resonance position and the resonance intensity with spacing

Fig. 6. Electric field distributions at the interface for Ag nanostructures with spacing of 50, 150, 250, and 320 nm

Fig. 7. Comparison of the influence on peak position resulted from diameter and spacing

Fig. 8. (a) Extinction spectra of Ag nanostructures with different substrate refractive indices; (b) variation of the resonance position and the resonance intensity with substrate refractive index

Fig. 9. Electric field distributions at the interface for Ag nanostructures with substrate refractive index of 1, 1.5, 2 and 2.5