Optimizing Nanoparticle Designs for Ideal Absorption of Light

Metallic nanoparticles and more recently dielectric nanoparticles are receiving tremendous attention due to their ability to concentrate light energy into volumes at the nanometer scale. Optimizing the absorption of light by suitably designed nanoparticles is of crucial importance for a wide range of applications including optical antennas, light harvesting, thermoplasmonics and local surface plasmon resonance sensing.

In an article recently published in ACS Photonics, we develop a new conceptual framework to achieve ideal absorption of light by metallic and dielectric particles. Our main results:
- We provide analytical formulations Eq.(16) describing the conditions to reach ideal absorption up to nanoparticle sizes of several hundreds of nanometer.
- Being analytical, these formulas are of immediate use for other researchers to optimize absorption in nanoparticles.
- The approach covers the important experimental case of core-shell nanoparticles which can satisfy the ideal light absorption condition over the full visible spectrum.
- We also address the problem of light absorption by dielectric and lossy particles, like silicon, that can exhibit both electric and magnetic Mie resonances.
- Our method enables the calculation of non-fundamental ideal absorption modes.