Electrodynamic response of a colloid ensemble with allowance for the influence of distant nanoparticles

The optical properties of a colloid consisting of nanoparticles are investigated on the example of interaction of three dielectric particles consisting of nonresonant atoms (whose natural transition frequencies are far from the radiation frequency) with interstitial barium atoms in the field of external optical radiation. On the basis of integrodifferential equations, expressions for the electric and magnetic fields in the wave zone are derived. The influence of distant neighbors in the ensemble on the light-scattering properties of a nanoparticle is considered, and the condition of applicability of the frequently used two-particle approximation is obtained. The spectrum of the system is investigated, and an additional resonant peak at the natural frequency of the isolated particle caused by the distant neighbor is established. Under some specific conditions, the additional peak intensity may exceed the main peak intensity of the optical near-field resonance in the two-particle system. __________ Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 8, pp. 3–11, August, 2006.