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Plasmon hybridization in pyramidal metamaterials: a route towards ultra-broadband absorption

Lobet, Michael; Lard, Mercy LU ; Sarrazin, Michael; Deparis, Olivier and Henrard, Luc (2014) In Optics Express 22(10). p.12678-12690
Abstract
Pyramidal metamaterials are currently developed for ultra-broadband absorbers. They consist of periodic arrays of alternating metal/dielectric layers forming truncated square-based pyramids. The metallic layers of increasing lengths play the role of vertically and, to a less extent, laterally coupled plasmonic resonators. Based on detailed numerical simulations, we demonstrate that plasmon hybridization between such resonators helps in achieving ultra-broadband absorption. The dipolar modes of individual resonators are shown to be prominent in the electromagnetic coupling mechanism. Lateral coupling between adjacent pyramids and vertical coupling between alternating layers are proven to be key parameters for tuning of plasmon... (More)
Pyramidal metamaterials are currently developed for ultra-broadband absorbers. They consist of periodic arrays of alternating metal/dielectric layers forming truncated square-based pyramids. The metallic layers of increasing lengths play the role of vertically and, to a less extent, laterally coupled plasmonic resonators. Based on detailed numerical simulations, we demonstrate that plasmon hybridization between such resonators helps in achieving ultra-broadband absorption. The dipolar modes of individual resonators are shown to be prominent in the electromagnetic coupling mechanism. Lateral coupling between adjacent pyramids and vertical coupling between alternating layers are proven to be key parameters for tuning of plasmon hybridization. Following optimization, the operational bandwidth of Au/Ge pyramids, i.e. the bandwidth within which absorption is higher than 90%, extends over a 0.2-5.8 m wavelength range, i.e. from UV-visible to mid-infrared, and total absorption (integrated over the operational bandwidth) amounts to 98.0%. The omni-directional and polarization-independent high-absorption properties of the device are verified. Moreover, we show that the choice of the dielectric layer material (Si versus Ge) is not critical for achieving ultra-broadband characteristics, which confers versatility for both design and fabrication. Realistic fabrication scenarios are briefly discussed. This plasmon hybridization route could be useful in developing photothermal devices, thermal emitters or shielding devices that dissimulate objects from near infrared detectors. (C) 2014 Optical Society of America (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Optics Express
volume
22
issue
10
pages
12678 - 12690
publisher
OSA
external identifiers
  • wos:000336957700127
  • scopus:84901260794
ISSN
1094-4087
DOI
10.1364/OE.22.012678
language
English
LU publication?
yes
id
8b13237f-2990-4362-93fb-b5827ef62939 (old id 4552145)
date added to LUP
2014-07-17 09:38:43
date last changed
2017-08-20 04:13:12
@article{8b13237f-2990-4362-93fb-b5827ef62939,
  abstract     = {Pyramidal metamaterials are currently developed for ultra-broadband absorbers. They consist of periodic arrays of alternating metal/dielectric layers forming truncated square-based pyramids. The metallic layers of increasing lengths play the role of vertically and, to a less extent, laterally coupled plasmonic resonators. Based on detailed numerical simulations, we demonstrate that plasmon hybridization between such resonators helps in achieving ultra-broadband absorption. The dipolar modes of individual resonators are shown to be prominent in the electromagnetic coupling mechanism. Lateral coupling between adjacent pyramids and vertical coupling between alternating layers are proven to be key parameters for tuning of plasmon hybridization. Following optimization, the operational bandwidth of Au/Ge pyramids, i.e. the bandwidth within which absorption is higher than 90%, extends over a 0.2-5.8 m wavelength range, i.e. from UV-visible to mid-infrared, and total absorption (integrated over the operational bandwidth) amounts to 98.0%. The omni-directional and polarization-independent high-absorption properties of the device are verified. Moreover, we show that the choice of the dielectric layer material (Si versus Ge) is not critical for achieving ultra-broadband characteristics, which confers versatility for both design and fabrication. Realistic fabrication scenarios are briefly discussed. This plasmon hybridization route could be useful in developing photothermal devices, thermal emitters or shielding devices that dissimulate objects from near infrared detectors. (C) 2014 Optical Society of America},
  author       = {Lobet, Michael and Lard, Mercy and Sarrazin, Michael and Deparis, Olivier and Henrard, Luc},
  issn         = {1094-4087},
  language     = {eng},
  number       = {10},
  pages        = {12678--12690},
  publisher    = {OSA},
  series       = {Optics Express},
  title        = {Plasmon hybridization in pyramidal metamaterials: a route towards ultra-broadband absorption},
  url          = {http://dx.doi.org/10.1364/OE.22.012678},
  volume       = {22},
  year         = {2014},
}