Open AccessUsing linear polarization for sensing and sizing dielectric nanoparticles
Author(s) -
Ángela Barreda,
J. M. Sanz,
Francisco González
Publication year - 2015
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.23.009157
Subject(s) - refractive index , optics , materials science , dielectric , polarization (electrochemistry) , mie scattering , linear polarization , light scattering , scattering , nanoparticle , fresnel equations , attenuation coefficient , optoelectronics , physics , nanotechnology , laser , chemistry
The spectral evolution of the degree of linear polarization (PL) at a scattering angle of 90° is studied numerically for high refractive index (HRI) dielectric spherical nanoparticles. The behaviour of PL(90°) is analysed as a function of the refractive index of the surrounding medium and the particle radius, and it is compared with the more conventional extinction efficiency parameter (Qext), usually used for sensing applications. We focus on the spectral region where both electric and magnetic resonances of order not higher than two are located for various semiconductor materials with low absorption. Although both Qext and PL(90°) are identifiers of the refractive index of the surrounding medium, the spectral of PL(90°) has only a small, linear dependence on nanoparticle size R. This weak dependence makes it experimentally feasible to perform real-time retrievals of both the refractive index of the external medium and the NP size R.