Figure 7

Near-field distribution of the square of electric field density on a silver particle scattering light λ=496 nm away from resonance with different sizes (a–d), where the dielectric constant is ε=−9.56+0.31i (the radius R=2 nm, E_max²=14E₀²; R=20 nm, E_max²=16E₀²; R=200 nm, E_max²=17E₀²; R=500 nm, E_max²=16E₀²), dielectric function and near-field distribution of electric field density on a small particle at the resonance condition for gold (e, f) and silver (g, h). In f, λ=481 nm, the radius of sphere is R=1.6 nm, dielectric constant is ε=−2.0+4.4i and E_max²=11E₀². In h, λ=354 nm, the radius of sphere is R=1.6 nm, the dielectric constant is ε=−2.0+0.28i and E_max²=457E₀².