Resonant electromagnetic scattering and light trapping by dielectric particle structures: Multipole approach

Resonant electromagnetic scattering and light trapping by dielectric particle structures: Multipole approach

Andrey Evlyukhin
Institute of Quantum Optics, Leibniz Universität Hannover, 30167 Hannover, Germany

The general principles of the multipole approach for explaining resonant electromagnetic scattering 
and the effect of mode trapping (concentration of electromagnetic energy on the subwavelength 
scale) by dielectric particle structures are discussed. The origins and development of modern dielectric 
photonics are first outlined, followed by the basic points of the theory of multipole response of 
resonant systems. It is shown how the configurational and geometrical parameters of high-refractive-index particle structures influence their optical response. In particular, the spectral multipole 
resonances of single non-spherical silicon nanoparticles depending on the overlap of their different 
multipole modes are discussed. The properties of two-dimensional periodic arrays of particles 
(metasurfaces) are discussed on the basis of the multipole decomposition of their reflection and 
transmission coefficients. The emergence and suppression of resonances in the reflection or 
transmission spectra of light in metasurfaces are presented as the result of interference between 
waves emitted by several multipole moments excited in their structural blocks. In particular, the 
mechanisms leading to the realization of the anapole (non-scattering) and trapped mode effects are 
considered.