Effect of a dielectric shell of a silver nanoparticle on the spectral position of the plasmon resonance of the nanoparticle in photochromic glass

The behavior of the spectral position of the absorption band of colloidal silver in photochromic glass is analyzed in relation to the variation in the refractive index of a thin layer of the medium (shell) that surrounds silver nanoparticles. It is shown that the appearance of a shell with a high refractive index leads to a long-wavelength shift in the plasmon absorption band of silver nanoparticles. These results make it possible to explain particular features of the absorption spectrum of photothermorefractive glasses.