Electromagnetic Scattering and Optical Properties of Spherical Nanoparticle Systems

The interaction of light with spherical nanoparticles is governed by a balance of absorption, scattering and near-field enhancement that depends sensitively on particle size, composition and surrounding medium. Classical routes to describe these phenomena include exact solutions of Maxwell’s equations for homogeneous spheres, yielding far-field scattering efficiencies, phase functions and extinction cross sections. At optical frequencies metallic spheres support surface plasmon resonances that concentrate electromagnetic energy in subwavelength volumes, driving applications in biosensing, surface-enhanced spectroscopy, photocatalysis and photovoltaic light trapping. Dielectric nanoparticles exhibit low-loss Mie resonances that enable directional scattering and novel metasurface designs. The dielectric environment, multilayer architectures and particle assemblies give rise to collective coupling, modified radiative decay rates and Fano-type interference. Modern approaches combine effective medium theories, discrete dipole approximations and rigorous T-matrix formalisms to capture complex host absorption, near-field interactions and the transition from single-particle behaviour to multiple scattering in dense systems. This body of work underpins the rational design of nanostructures for optical filtering, quantum-efficiency enhancement and nanoscale optical logic devices.

Research from Nature Portfolio

Recent studies have refined effective medium models to characterise the modulation of plasmonic resonances in oxide films doped with resonant and non-resonant metal nanoparticles. By varying nanoparticle radius, concentration and host-film thickness, researchers have demonstrated how surface plasmon peaks shift and broaden in response to changes in the surrounding lattice symmetry. This work reveals that nanoparticle concentration is the dominant factor in transmittance modulation, while the monoclinic form of the oxide host amplifies visible-region plasmonic signals more strongly than the orthorhombic phase. Such insights guide the optimisation of nanocomposite coatings for tunable optical filters and energy-harvesting layers.

Electromagnetic Scattering and Optical Properties of Spherical Nanoparticle Systems publication trend

The graph below shows the total number of articles in electromagnetic scattering and optical properties of spherical nanoparticle systems across all publications each year (not limited to Nature Index journals).

Technical terms

Electromagnetic scattering: Deflection of incident light by a particle, yielding redistributed far-field and near-field energy.

Surface plasmon resonance (SPR): Collective oscillation of conduction electrons at a metal–dielectric interface that enhances local fields.

Effective medium theory: Approximate description of a composite by averaging its microscopic optical properties into a homogeneous medium.

Discrete dipole approximation (DDA): Numerical method representing a scatterer as an array of polarizable points to solve Maxwell’s equations.

Extinction cross section: Effective area through which a particle removes energy from an incident beam by absorption and scattering.

Tamm plasmon: Localised surface state at the interface between a metal and a photonic crystal, analogous to electronic Tamm states.

References

1. Effective medium theory to the description of plasmonic resonances: Role of Au and Ti nanoparticles embedded in MoO3 thin films. Scientific Reports (2020).
2. Discrete dipole approximation method for electromagnetic scattering by particles in an absorbing host medium.. Optics Express (2021).
3. High-Q Tamm plasmon-like resonance in spherical Bragg microcavity resonators.. Optics Express (2024).
4. Extinction and attenuation by voids in absorbing host media.. Optics Express (2023).