Harbin Engineering University

Photonics Asia 2014, 9 October 2014

Coherent perfect absorber

based on metamaterials

Guangyu Nie, Quanchao Shi, Zheng Zhu, and Jinhui Shi

Harbin Engineering University (China)

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Outline

1. Introduction

2. Coherent Perfect Absorption

3. Simulation Results

4. Conclusions

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Metamaterials

Negative refraction

Perfect lensInvisibility cloak

Polarization rotation

Asymmetric transmission

Perfect absorber

Natural materials

1.Introduction

Metamaterials are artificial materials engineered to

have properties that may not be found in nature.

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Tunable Optical Properties

Coherent Perfect Absorption (CPA)

Metamaterial absorbers

N. I. Landy, et al. Phys. Rev. Lett. 100,

207402 (2008)

X. L. Liu, et al.

Phys. Rev. Lett. 104,

207403 (2010)

X. L. Liu, et al. Nano Lett. 10, 2342 (2010)

J. M. Hao, et al. Appl. Phys. Lett. 96, 251104

(2010)

1.Introduction

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S. A. Mousavi, et al, Appl. Phys. Lett. 105, 011906 (2014)

Coherent perfect absorption (CPA)

M. Kang, et al, Opt. Lett. 39(16), 4879 (2014) J. Zhang, et al, Light: Sci. Appl. 1, e18 (2012)

1.Introduction

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J. F. Zhang, et al, Opt. Express 22, 12524 (2014)

Input Beam A Input Beam B

Output Beam B Output Beam A

2. Coherent Perfect Absorption (CPA)

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Coherent excitation-selective spectroscopy in planar metamaterials

(1) (2)

Coherent spectroscopy of the slit nanoantenna

metamaterial with dominant electric dipolar response.

Coherent spectroscopy of the “magnetic wire” metamaterial

with dominant magnetic dipolar optical response.

(a) The unit cell of the metamaterial.

(b) Simulated absorption A, refection R and transmission T

spectra upon travelling-wave excitation.

(c) Simulated and (d) measured standing-wave absorption

spectra at the electric and magnetic antinodes.

X. Fang, et al, arXiv: 1312.0524 (2013)

2. Coherent Perfect Absorption

Coherent excitation-selective spectroscopy

can be realized in two types of metamaterials.

Multiple band absorption can be realized in

one structure ?

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Engineering electromagnetic responses of

bilayered metamaterials based on Fano resonances

J. H. Shi, et al, Appl. Phys. Lett. 103, 071906 (2013)

In the 0° and 180° -twisted metamaterials, there are three separated absorption peaks,

respectively.

2. Coherent Perfect Absorption

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n

z x

y z

θ =180° θ =0°

Virtual infinite array

Bilayered asymmetrically split rings (ASRs)

FR4 printed

circuit board

β

α

Metamaterial Design2. Coherent Perfect Absorption

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n

z x

y

r = 5.6mm

β = 140°

α = 160° d =

15 m

m

w = 0.8 mm

t = 1.6 mm

Coherent control of the bilayered metamaterials at selected resonant

frequencies of (a) 4.89 GHz for θ=0° and (b) 5.37 GHz for θ=180°.

S : Total output intensity A : Absorption of the metamaterials S1&S2 : Signal & Control output intensity

3.Simulation Results

Selective coherent perfect absorbers can be realized based on

coherent control technique.

Multiple band absorption can be alternately switched on/off by

modulating the phase difference between two input beams.

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3.Simulation Results

The in-phase state holds the same current oscillations and pairs of ASRs can be

regarded as a single electric dipole. The out-of-phase state results from anti-symmetric

current oscillations, each pair of ASRs effectively forms a magnetic dipole.

41

52

63

Magnetic dipole

Electric dipole

θ = 0° θ = 180°

X-component of the instantaneous surface current density

in the 0° and 180°-twisted bilayered ASR.

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θ = 0°

t mm

+0.5 mm

+0.5 mm

+0.5 mm

Changing tV

V

Input Beam A Input Beam B

Output Beam B Output Beam A

n

z x

y

r = 5.6mm

β = 140°

α = 160° d =

15 m

m

t

w = 0.8 mm

Absorption spectra of the bilayered ASRs for x-polarized beams.

3.Simulation Results Changing t

High-quality absorption is achieved at the thickness of t = 1.5 mm and 2.0 mm.

By changed the coupling strength determined by the thickness of the dielectric

layer, two absorption peaks in t = 2.0 mm can be totally separated.

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θ = 180°

+0.5 mm

Changing tt mm

+0.5 mm

+0.5 mm

V

V

n

z

x

y z

Input Beam A Input Beam B

Output Beam B Output Beam A

3.Simulation Results

Absorption spectra of the bilayered ASRs for x-polarized beams.

Changing t

High-quality absorption is achieved at the thickness of t = 2.0 mm.

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α+ 5°

+ 5°

+ 5°

Changing

asymmetry

θ = 0°

Input Beam A Input Beam B

Output Beam B Output Beam A

n

z x

y

r = 5.6mm

β = 140°

α = 160° d =

15 m

m

t = 1.6 mm

w = 0.8 mm

Absorption spectra of the bilayered ASRs for x-polarized beams.

3.Simulation Results Changing asymmetry of ASRs

The selective coherent perfect absorbers with high absorption have been

achieved depending on the phase difference between two coherent beams.

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Conclusions

We achieved the selective coherent perfect absorption in

bilayered metamaterials.

The selective coherent perfect absorption is realized

depending on electromagnetic mode switching effect.

We can engineer coherent perfect absorption by changing the

thickness of the dielectric layer or the asymmetry of the ASR.

The coherently controlled metamaterials will be promising

candidates for designing selective multiband absorbers at any

frequencies from the microwave to optical range.

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Thank you for your attention.