Characterizing the Backscattered Spectrum of Mie Spheres
Abstract
This study describes both experimentally and theoretically an important hitherto undiscovered feature of the scattering of micron_sized spherical objects when illuminated with highly focused circularly polarized light. This is a regime of high experimental relevance which has not been described in full detail. The experiments are complemented with the analytical formulas explaining the field scattered directed toward the backward hemispace. In particular, it is proven that this field shows a very regular oscillatory dependency with the optical size. This phenomenon is typically hidden in the total scattered field, as the field is scattered much less toward the backward hemisphere than toward the forward one. These regular oscillations are measured experimentally. It is proven that, by analyzing them, it is possible to determine the index of refraction of isolated micron_sized particles, opening new paths for applications in sensing and metrology.
Keywords
Cite
@article{arxiv.2601.23194,
title = {Characterizing the Backscattered Spectrum of Mie Spheres},
author = {Martín Molezuelas-Ferreras and Álvaro Nodar and María Barra-Burillo and Jorge Olmos-Trigo and Jon Lasa-Alonso and Iker Gómez-Viloria and Elena Posada and J. J. Miguel Varga and Rubén Esteban and Javier Aizpurua and Luis E. Hueso and Cefe Lopez and Gabriel Molina-Terriza},
journal= {arXiv preprint arXiv:2601.23194},
year = {2026}
}