Article review and presentation on basics of using metamaterials as optical perfect absorbers Metamaterial Course Final Project ( Optional Graduate Course ) Dr. Leyla Yousefi

1. Using Metamaterials as
Optical Perfect Absorbers
Sepehr Ahmadzadeh
University of Tehran
1

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Outline
1. Introduction to Electromagnetic Wave Perfect Absorber
2. Theory
3. Metamaterial Perfect Absorbers (MPA)
4. Optical Perfect Absorbers
5. Recent Papers
6. Conclusion

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Introduction
Electromagnetic wave Absorber Absorption of Incident
Electromagnetic Wave
In Operating Frequency
Frequency Microwave to Optical Regime
Types Resonant Absorbers
Broadband Absorbers

4. 4
Resonant Absorbers
Radar Absorber Material Stealth Technology
Reduce RCS
Crossed Grating Absorber Metal Plane with an
Etched Shallow Periodic
Grid
[1]
[1]

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Broadband Absorbers
Geometric Transition
Absorbers
Lossy materials using shapes such
as pyramids
[1]

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Near Unity Absorber All Incident Wave is
Absorbed at the Operating
Frequency
Transmissivity, Reflectivity and scattering are disabled.
Unity absorption
Zero Reflection
Zero Transmission
Transparency in Optical
Regime !?

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Electromagnetic Wave Absorption Theory
Electromagnetic Wave Incidence
Reflection
Transmission
Absorption
Scattering
Excite Surface Electromagnetic Waves
Average Roughness Ignore Scattering Effects
Propagation Length SEW (mostly plasmons)

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Electromagnetic Wave Absorption Theory (Cont’d)
In order for an incident EM wave to couple to a surface wave
we must have
1. Matching between incident wavevector
and dispersion of surface
2. The loss of the surface for propagation
of our SEW

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Electromagnetic Wave Absorption Theory (Cont’d)
If is sufficiently large, SEW may be a form of loss.
Re-radiation is possible too, e.g. our surface is curved.
Finally Reflection ( )
Transmission ( )
Absorption ( )

10. Case I
Consider a slab of thickness d of magneto-dielectric medium
backed by a highly conductive metallic ground
plane.
10
NO TRANSMISSION
For

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Case I (Cont’d)
Reflection from metallic ground plane ?
Sufficient thickness of d
Sufficient loss

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Case II
Consider a slab of thickness d of magneto-dielectric medium
embedded in vacuum.

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a. Magneto-dielectric
medium backed by a
metallic ground plane
b. Permittivity and
Permeability of the
magneto-dielectric
material
c. Magneto – dielectric
medium of thickness d
[1] Adv. Mater. 2012, 24, OP98–OP120

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Metamaterial Perfect Absorbers (MPA)
Arrays of structured subwavelength elements
Typically highly conductive metals
such as copper, gold, or silver
MMs are geometrically scalable (Self-Scaling)

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(Continued)Metamaterial Perfect Absorbers (MPA)
As an effective medium
By manipulating resonances in &
Absorb both electric
and magnetic field
By matching &
Impedance matching to free space Minimizing reflectivity

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[2]Wide-angle infrared
absorber based on negative
index plasmonic metamaterial
Yoav Avitzor, Yaroslav Urzhumov, Gennady Shvets
Physical Review
January 13, 2009

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 Wide-angle absorber of infrared radiation
 Based on anisotropic impedance matched
negative index material
 100% Absorption up to to the normal
 Constructed from plasmonic wires
Characteristics PIMNIM Structure
[2]Wide-angle infrared
absorber based on
negative index
plasmonic metamaterial
Physical Review
December 2009

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Theoretical Background
Semi-infinite slab of a lossy MM
• Incident in the x-z plane
• Relevant components
Engineered structure ( diagonal tensors)

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Theoretical Background (Cont’d)
At normal incidence in the x-z plane
absorber’s material impedance =
At specific wavelength if the structure’s impedance
is matched to that of vacuum
Assuming that and
we find that

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Angular dependence
of the absorption
Dashed
Line
Dashed Dotted
Line
[2]Wide-angle infrared absorber based on negative index plasmonic metamaterial
Physical Review
December 2009

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[2]Wide-angle infrared absorber based on negative index plasmonic metamaterial
Physical Review
December 2009
Extracted effective
dielectric permittivity
and magnetic
Permeability of the
PIMNIM structure.
Reflectance vanishes at
because
nm
scale
Results

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Reflectance,
transmittance and
absorbance at normal
incidence of a single
PIMNIM layer.
Simulation Results
[2]Wide-angle infrared absorber based on negative index plasmonic metamaterial
Physical Review
December 2009
nm
scale

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[3] Optically thin composite resonant
absorber at the near infrared band: a
polarization independent and spectrally
broadband configuration
Kamil Alici, Adil Turhan, Ekmel Ozbey
18 July 2011 / Vol. 19, No. 15 / OPTICS EXPRESS 14267

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 Electrical and magnetic impedance matching at the near-infrared
regime.
 Consist of four main layers : 1. A metal back plate
2. Dielectric spacer
3&4. Two artificial layers
 Polarization independent broad band perfect absorber
 Wide angle incidence due to the subwavelength unit
cell
 Applications in Thermal photovoltaic , Sensors , ...
Characteristics

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Transmission
Reflection
Spectroscopy
Using Ocean Optics
Spectrometer
Visible Regime 600nm – 1000nm
Near IR 900nm – 1700nm
[3] Optically thin composite
resonant absorber at the near
infrared band: a polarization
independent and spectrally
broadband configuration
Structure

26. Up to this point
Normal incidence OK
Single Polarization OK
Gold-only SRR
26
Results
[3] Optically thin composite resonant absorber at the near infrared
band: a polarization independent and spectrally broadband
configuration
Center Freq. of Operation
250 THz

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Adding resistive sheet
(thin titanium)
Between the MM and
dielectric
1. Resistive sheet
resonant absorber
2. MM absorber
[3] Optically thin composite resonant absorber at the near infrared
band: a polarization independent and spectrally broadband
configuration

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Simulated Results
Oblique Incidence
Absorption remains more
than 70% up to
60 deg angle of incidence
[3] Optically thin composite
resonant absorber at the near
infrared band: a polarization
independent and spectrally
broadband configuration

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[4] Optical metamaterial absorber
based on leaf-shaped cells
Weiren Zhu, Xiaopeng Zhao, Boyi Gong
Longhai Liu, Bin Su
Applied Physics A 102: 147–151 (2011)

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Characteristics
 IR MM Absorber composed of metallic leaf-shaped cells, dielectric
substrate, and continuous metallic film
 Absorptivity of 99.3% at the IR frequency of 126.7 THz
 fabricated with an electrochemical deposition technique
 Support different incident angles and radiation modes
 Applications such as IR imaging systems, thermal bolometers,
Optical bi-stable switches

31. Structure
31
Numerical simulations
Using CST Microwave
Studio
Silver leaf-shaped cells
[4] Optical metamaterial absorber based on leaf-shaped cells

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Results
Simulated Results of the structure in the Optical Regime
[4] Optical metamaterial absorber based on leaf-shaped cells

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[4] Optical metamaterial absorber based on leaf-shaped cells
Angular
dependence
of the
absorptivity
of the
infrared
metamaterial
absorber

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[5] Perfect absorbers on curved surfaces
and their potential applications
Rasoul Alaee , Christoph Menzel , Carsten Rockstuhl,
and Falk Lederer
30 July 2012 / Vol. 20, No. 16 / OPTICS EXPRESS 18376

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 Perfect metamaterial absorber applied on curved surfaces
 1. Suppression of back-scattered light from the covered objects
2. Rendering it cloaked in reflection
3. Optical black holes
 suppression of spurious back-scattered light for example in
Radar absorbers
Characteristics
 Flexible polymer film structure

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Omni directional Perfect
Absorber
Perfect Absorber on Planar Surface
Ground plane and
metallic wire made
from silver
[5] Perfect absorbers on curved surfaces and their potential applications
Anti symmetric
current distribution in
the nanowire and the
ground plane

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Hz- component at resonance
for a plane wave incident at an
absorber on curved surface
[5] Perfect absorbers on curved surfaces and their potential applications

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Conclusion
1. Theory of EM absorbing materials
2. What is Perfect Absorber ?
3. Two specific types of PA
4. Using Metamaterial as a PA
5. Recent papers and applications

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References
[1] Metamaterial Electromagnetic Wave Absorbers ; Adv. Mater.
2012, 24, OP98–OP120
[2] Y. Avitzour, Y. A. Urzhumov, and G. Shvets, “Wide-angle
infrared absorber based on a negative-index plasmonic
metamaterial,” Phys. Rev. B79, 045131 (2009)
[3] Optically thin composite resonant absorber at the near
infrared band: a polarization independent and spectrally
broadband configuration ; July 2011 / Vol. 19, No. 15 / OPTICS
EXPRESS 14267
[4] Optical metamaterial absorber based on leaf-shaped cells
Applied Physics A 102: 147–151 (2011)
[5] Perfect absorbers on curved surfaces and their potential
applications ; 30 July 2012 / Vol. 20, No. 16 / OPTICS EXPRESS

40. 40
[6] N. I. Landy, S. Sajuyigbe, J. J. Mock, D. R. Smith, and W. J. Padilla,
Perfect metamaterial absorber, Phys. Rev. Lett. 100, p. 207402, 2008
[7] Jiaming Hao, Jing Wang, Xianliang Liu, Willie J. Padilla, Lei Zhou,
and Min Qiu,High performance optical absorber based on a plasmonic
metamaterial, Appl. Phys. Lett.96, 2010
[8] Design of highly absorbing metamaterials for Infrared frequencies
30 July 2012 / Vol. 20, No. 16 / OPTICS EXPRESS 17508

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