Imperial College London

ProfessorStefanMaier

Faculty of Natural SciencesDepartment of Physics

Lee-Lucas Chair in Experimental Physics
 
 
 
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Contact

 

+44 (0)20 7594 6063s.maier Website CV

 
 
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Location

 

Huxley 903Huxley BuildingSouth Kensington Campus

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Summary

 

Publications

Citation

BibTex format

@article{Hüttenhofer:2021:10.1021/acsphotonics.1c00238,
author = {Hüttenhofer, L and Tittl, A and Kühner, L and Cortés, E and Maier, SA},
doi = {10.1021/acsphotonics.1c00238},
journal = {ACS Photonics},
pages = {1469--1476},
title = {Anapole-assisted absorption engineering in arrays of coupled amorphous gallium phosphide nanodisks},
url = {http://dx.doi.org/10.1021/acsphotonics.1c00238},
volume = {8},
year = {2021}
}

RIS format (EndNote, RefMan)

TY  - JOUR
AB - Broadband solar light harvesting plays a crucial role for efficient energy conversion. Anapole excitations and associated absorption engineering in dielectric nanoresonators are a focus of nanophotonic research due to the intricate combination of nonradiating modes and strong electromagnetic field confinement in the underlying material. The arising high field strengths are used for enhanced second-harmonic generation and photocatalysis, where devices require large areas with closely spaced nanoresonators for sizable photonic yields. However, most anapole studies have so far been carried out at the single-particle level, neglecting the influence of anapole–anapole interactions. Here, we present a systematic study of coupling mechanisms in rectangular arrays of amorphous GaP nanodisks that support anapole excitations at 600 nm, which is within the lossy spectral regime of the material. Our experimental findings show that maximum visible light extinction by the array and maximum absorption in the GaP are not achieved by the densest packing of resonators. Counterintuitively, increasing the array periodicities such that collective effects spectrally overlap with the anapole excitation of a single particle leads to an absorption enhancement of up to 300% compared to a single disk. An analysis of coupling in one- and two-dimensional arrays with polarization-dependent measurements and numerical simulations allows us to discriminate between coupling interactions parallel and perpendicular to the polarization axis and evaluate their strengths. Utilizing a multipolar decomposition of excitations in single nanodisks embedded in one-dimensional arrays, we can attribute the coupling to enhanced electric and toroidal dipoles under variation of the interparticle spacing. Our results provide a fundamental understanding of tailored light absorption in coupled anapole resonators and reveal important design guidelines for advanced metasurface approaches in a wide range of energy
AU - Hüttenhofer,L
AU - Tittl,A
AU - Kühner,L
AU - Cortés,E
AU - Maier,SA
DO - 10.1021/acsphotonics.1c00238
EP - 1476
PY - 2021///
SN - 2330-4022
SP - 1469
TI - Anapole-assisted absorption engineering in arrays of coupled amorphous gallium phosphide nanodisks
T2 - ACS Photonics
UR - http://dx.doi.org/10.1021/acsphotonics.1c00238
UR - https://pubs.acs.org/doi/10.1021/acsphotonics.1c00238
UR - http://hdl.handle.net/10044/1/89603
VL - 8
ER -