Calculation of Giant Combination Light Scattering on a Dipole Located between Metallic Nanoparticle and Metallic Nanofilm on Substrat (TERS Theory)

A metallic nanoparticle (NP) located near the film acts as a nanoantenna. Surface plasmons, excited by light in a particle and in a film, transform the electromagnetic field, confine it and strongly amplify it in the gap between the particle and the film. The enhancement of the field depends on many factors: the size and shape of NP, the permeability of all materials, the wavelength of light, the thickness of the film, the angle of the light beam and very much from the gap between the particle and the film. The amplification of the field in a narrow gap (~ 1 nm) can be 10^3 or more and the enhancement of Raman radiation can reach enormous values of ~ 10^10–10^11.

Lightning Strike Protection and EMI Shielding of Fiber Reinforced Composite Using Gold and Silver Nanofilms

Carbon fiber reinforced composites are very much imperative to future-generation aircraft structures. However, lightning strike protection (LSP) and electromagnetic interference (EMI) are main concerns. Carbon fibers have very good mechanical properties with the best strength-to-weight ratio, but they are very poor conductors of electricity. These fibers must be reinvented to increase the surface conductance to provide high electrical conductivity to the aircraft structure. The present study deals with preparing composite sandwich structures of carbon fibers used for commercial nacelle applications subject to lightning strike effects with different metallic nanofilm of gold (Au) and silver (Ag) measuring approximately 100 nm. These metallic nanofibers were co-cured on the top layers of composite panels during vacuum curing process. In our laboratory, lightning strike results for a composite sandwich structure using nanofilms were obtained to observe lightning strike damage and structural tolerance necessary to observe the damage tolerance capability. Resistance of composite panels with metallic nanofilm under various strains was studied. It was found that resistance of the metallic nanofilm increased under strain. The voltage was found to be low; hence, an increase in current would help to reduce the damage on composite panels due to lightning strikes, and the same theory would be applicable to EMI. No EMI was absorbed or reflected in the nanofilm using the P-static test. When lightning strikes were applied to composite coupons, the resulting damage from the currents was reduced on those with metallic nanofilms.

ANALYSIS OF SURFACE PLASMONS EXCITATIONS FROM FABRICATION DEFECTS OF METALLIC NANOFILM WITH NONSYMMETRICAL AND FINITE GRATING-LIKE CORRUGATION

The influence of fabrication errors of metallic nanofilm with the grating-like and nonsymmetrical corrugation on one or two sides on surface plasmons resonance is analyzed by using boundary integral method. The scattering cross-section and the near-field intensity distribution of its corresponding resonant wavelengths for the finite grating-like nanostructure with or without fabrication defects are numerical investigated. The results show that the resonant wavelength is influenced by the fabrication flaws. More detailed directions of the electric flux lines around the metallic grating-like nanostructure and the near-field intensity distribution indicate that the excitation of surface electrons is influenced. This investigation will provide useful information for the fabrication of the metallic grating-like nanostructure and the experimental error analysis of the scientists.