Anapole-Enhanced Intrinsic Raman Scattering from Silicon Nanodisks
Journal article, 2018

Enhancement of inelastic light emission processes through resonant excitation usually correlates with enhanced scattering of the excitation light, as is for example typically the case for surface-enhanced fluorescence and Raman scattering from plasmonic nanostructures. Here, we demonstrate an unusual case where a reverse correlation is instead observed, that is, we measure a multifold enhancement of Raman emission along with suppressed elastic scattering. The system enabling this peculiar effect is composed of silicon nanodisks excited in the so-called anapole state, for which electric and toroidal dipoles interfere destructively in the far-field, thereby preventing elastic scattering, while the optical fields in the core of the silicon particles are enhanced, thus, amplifying light-matter interaction and Raman scattering at the Stokes-shifted emission wavelength. Our results demonstrate an unusual relation between resonances in elastic and inelastic scattering from nanostructures and suggest a route toward background-free frequency conversion devices.

Raman scattering

high-index materials

silicon nanoparticles

anapole

Author

Denis Baranov

University of Gothenburg, Department of Physics

Ruggero Verre

Chalmers, Physics, Bionanophotonics

Pawel Karpinski

Chalmers, Physics, Bionanophotonics

Mikael Käll

Chalmers, Physics, Bionanophotonics

ACS Photonics

2330-4022 (eISSN)

Vol. 5 7 2730-2736

Subject Categories

Atom and Molecular Physics and Optics

Other Physics Topics

Condensed Matter Physics

DOI

10.1021/acsphotonics.8b00480

More information

Latest update

8/31/2018