Experimental results of dependent light scattering by two spheres

Abstract

Microwave analog measurements of the forward scattering produced by two spheres yield the extinction as a function of sphere separation for the case of one sphere's being shadowed by the other. The effects of dependent scattering are obvious up to a separation distance of about ten sphere diameters. Side-scattering measurements show a resonance when the axis of the two-sphere system is in the scattering plane and bisects the scattering angle. The magnitude of at least one measured resonance is a factor of 44 larger than the scattering that is due to a single sphere.

Subdiffraction optical resolution of a gold nanosphere located within the nanojet of a Mie-resonant dielectric microsphere

“…Scattering by a bi-sphere system, which has potential applications to biomedical, atmospheric and ocean optics, has been investigated extensively over the last forty years, as for example [1][2][3][4][5][6][7][8]. In the past, the primary interest has involved scattering by a pair of spheres of similar size and composition.…”

Light-scattering form factors of asymmetric particle dimers from heteroaggregation experiments

“…Initially, such tests were carried out in the microwave region, where the scattering could be directly tested on macroscopic objects. 18,19 More recently, such a comparison was carried out in the optical regime on individual aggregates composed of a few primary particles, but some uncertainties concerning the particle size, which was supplied by the manufacturer, remained. 20 A different approach to study the properties of particle dimers in the optical regime is to focus on the initial stages of an aggregating suspension of colloidal particles.…”

Optical Absorption Coefficient of a Dispersion of Clusters Composed of a Large Number of Spheres

“…It is well known that, from the point of view of their optical properties, many common aerosols cannot be considered as composed of spherical particles (Kerker, 1963;Liu et al, 1984). In fact, the observed macroscopic optical constants of aerosols are seldom consistent with those calculated on the ground of single-particle scattering properties obtained using Mie theory (Kerker, 1963;Wang et al, 1981;Milham, 1976). On the other hand, the problem of scattering by an irregularly shaped particle is a rather hard one, and its difficulties are not easily overcome when the size of the scatterer is not small in comparison to the wavelength of the incident light and/or its refractive index differs appreciably from that of the surrounding medium (Kerker, 1963; Barber and Wang, 1978).…”