The aim of this chapter is to investigate the effect of size, shape and environment on the optical properties of metallic nanoparticles in a large spectral range (λ = 300–900 nm) using quasi-static approximation for nanoparticles of sizes (D = 10–40 nm) and Mie theory for nanoparticles of sizes (D = 40–100 nm). Extinction (scattering and absorption) cross-sectional spectrum of nanoparticles is obtained for different diameters embedded in different matrices. Collective oscillation of electrons in conduction band in metallic nanoparticles is known as surface plasmon resonance (SPR) phenomena. SPR of metallic nanoparticles has significant applications in optics, communications and biosensors. We present in this chapter the effects of the interparticle distance on the optical response of gold dimer nanoparticles of 100 nm diameter. The extinction spectra of dimer nanoparticles are calculated by using generalized Mie theory.
Part of the book: Noble and Precious Metals