Dark resonating states render an important role in curtailing the dominant radiative losses in various photonic structures like metamaterials (MMs), photonic crystals, waveguides, etc. Currently, radiative losses are the major degrading factors toward the strong confinement of electromagnetic radiation for MMs’ applications in sensing, imaging, filters, modulators, nonlinear studies, etc. Generally, the dark states cannot be excited through the direct interaction of electromagnetic radiations with the metastructures. However, indirect excitation at suitable structural asymmetries can trigger the evolution of dark resonating states or trapped modes. In this work, we have experimentally demonstrated mode hybridization of such dark (sub-radiant) resonating states without the direct involvement of interacting bright (super-radiant) states in a metasurface consisting of asymmetric split-ring resonators. Our study further reveals that the lattice mode plays a crucial role in determining the line shapes of the split (hybridized) modes. Such tuning of dark resonance modes can find potential applications in metasurfaces-based sensing, non-linear devices besides other potential applications desiring multi-channel strong field confinement.

1.
B.
Luk‘yanchuk
,
N. I.
Zheludev
,
S. A.
Maier
,
N. J.
Halas
,
P.
Nordlander
,
H.
Giessen
, and
T. C.
Chong
, “
The Fano resonance in plasmonic nanostructures and metamaterials
,”
Nat. Mater.
9
,
707
(
2010
).
2.
B.
Gallinet
and
O. J. F.
Martin
, “
Influence of electromagnetic interactions on the line shape of plasmonic Fano resonances
,”
ACS Nano
5
,
8999
(
2011
).
3.
P.
Chak
,
J. K. S.
Poon
, and
A.
Yariv
, “
Optical bright and dark states in side-coupled resonator structures
,”
Opt. Lett.
32
,
1785
1787
(
2007
).
4.
H.
Lu
,
X.
Liu
,
D.
Mao
, and
G.
Wang
, “
Plasmonic nanosensor based on Fano resonance in waveguide-coupled resonators
,”
Opt. Lett.
37
,
3780
3782
(
2012
).
5.
E.
Tekman
and
P. F.
Bagwell
, “
Fano resonances in quasi-one-dimensional electron waveguides
,”
Phys. Rev. B
48
,
2553
(
1993
).
6.
J.
Mäkitalo
,
M.
Kauranen
, and
S.
Suuriniemi
, “
Modes and resonances of plasmonic scatterers
,”
Phys. Rev. B
89
,
165429
(
2014
).
7.
J.
Valentine
,
J.
Li
,
T.
Zentgraf
,
G.
Bartal
, and
X.
Zhang
, “
An optical cloak made of dielectrics
,”
Nat. Mater.
8
,
568
571
(
2009
).
8.
M.
Manjappa
,
P.
Pitchappa
,
N.
Wang
,
C.
Lee
, and
R.
Singh
, “
Active control of resonant cloaking in a terahertz MEMS metamaterial
,”
Adv. Opt. Mater.
6
,
1800141
(
2018
).
9.
J. B.
Pendry
, “
Negative refraction makes a perfect lens
,”
Phys. Rev. Lett.
85
(
18
),
3966
3969
(
2000
).
10.
N. F.
Yu
,
P.
Genevet
,
M. A.
Kats
,
F.
Aieta
,
J. P.
Tetienne
,
F.
Capasso
, and
Z.
Gaburro
, “
Light propagation with phase discontinuities: Generalized laws of reflection and refraction
,”
Science
334
,
333
337
(
2011
).
11.
D. R.
Smith
,
J. B.
Pendry
, and
M. C. K.
Wiltshire
, “
Metamaterials and negative refractive index
,”
Science
305
,
788
(
2004
).
12.
R. A.
Shelby
,
D. R.
Smith
, and
S.
Schultz
, “
Experimental verification of a negative index of refraction
,”
Science
292
,
77
(
2001
).
13.
S.
Karmakar
,
D.
Kumar
,
R. K.
Varshney
, and
D.
Roy Chowdhury
, “
Strong terahertz matter interaction induced ultrasensitive sensing in Fano cavity based stacked metamaterials
,”
J. Phys. D: Appl. Phys.
53
(
41
),
415101
(
2020
).
14.
S.
Kaur
,
S.
Karmakar
,
K. M.
Devi
,
R. K.
Varshney
, and
D.
Roy Chowdhury
, “
Ultrasensitive terahertz sensing with broadside coupled polarization insensitive graphene metamaterial cavities
,”
Optik
248
,
168073
(
2021
).
15.
D. K.
Gramotnev
and
S. I.
bozhevolnyi
, “
Plasmonics beyond the diffraction limit
,”
Nat. Photonics
4
,
83
91
(
2010
).
16.
Z. H.
Jiang
,
S.
Yun
,
L.
Lin
,
J. A.
Bossard
,
D. H.
Werner
, and
T. S.
Mayer
, “
Tailoring dispersion for broadband low-loss optical metamaterials using deep-subwavelength inclusions
,”
Sci. Rep.
3
,
1571
(
2013
).
17.
P. R.
West
,
S.
Ishii
,
G. V.
Naik
,
N. K.
Emani
,
V. M.
Shalaev
, and
A.
Boltasseva
, “
Searching for better plasmonic materials
,”
Laser Photonics Rev.
4
,
795
(
2010
).
18.
V. A.
Fedotov
,
M.
Rose
,
S. L.
Prosvirnin
,
N.
Papasimakis
, and
N. I.
Zheludev
, “
Sharp trapped-mode resonances in planar metamaterials with a broken structural symmetry
,”
Phys. Rev. Lett.
99
,
147401
(
2007
).
19.
S.
Zhang
,
D. A.
Genov
,
Y.
Wang
,
M.
Liu
, and
X.
Zhang
, “
Plasmon-induced transparency in metamaterials
,”
Phys. Rev. Lett.
101
,
047401
(
2008
).
20.
R.
Singh
,
I. A. I.
Al-Naib
,
M.
Koch
, and
W.
Zhang
, “
Sharp Fano resonances in THz metamaterials
,”
Opt. Express
19
,
6312
6319
(
2011
).
21.
W.
Yu
,
H.
Meng
,
Z.
Chen
,
X.
Li
,
X.
Zhang
,
F.
Wang
,
Z.
Wei
,
C.
Tan
,
X.
Huang
, and
S.
Li
, “
The bright–bright and bright–dark mode coupling-based planar metamaterial for plasmonic EIT-like effect
,”
Opt. Commun.
414
,
29
33
(
2018
).
22.
Z.
Jia
,
L.
Huang
,
J.
Su
, and
B.
Tang
, “
Tunable plasmon-induced transparency based on monolayer black phosphorus by bright-dark mode coupling
,”
Appl. Phys. Express
13
,
072006
(
2020
).
23.
R.
Yahiaoui
,
J. A.
Burrow
,
S. M.
Mekonen
,
A.
Sarangan
,
J.
Mathews
,
I.
Agha
, and
T. A.
Searles
, “
Electromagnetically induced transparency control in terahertz metasurfaces based on bright-bright mode coupling
,”
Phys. Rev. B
97
,
155403
(
2018
).
24.
G. L.
Fu
,
X.
Zhai
,
H. J.
Li
,
S. X.
Xia
, and
L. L.
Wang
, “
Tunable plasmon-induced transparency based on bright-bright mode coupling between two parallel graphene nanostrips
,”
Plasmonics
11
,
1597
1602
(
2016
).
25.
S.
Hu
,
D.
Liu
, and
H.
Yang
, “
Electromagnetically induced transparency in an integrated metasurface based on bright–dark–bright mode coupling
,”
J. Phys. D: Appl. Phys.
52
,
175305
(
2019
).
26.
J.
Mei
,
C.
Song
, and
C.
Shu
, “
Active manipulation of dual transparency windows in dark–bright–dark mode coupling graphene metamaterial
,”
Opt. Commun.
488
,
126851
(
2021
).
27.
S.
Karmakar
,
S.
Banerjee
,
D.
Kumar
,
G.
Kamble
,
R. K.
Varshney
, and
D.
Roy Chowdhury
, “
Deep-subwavelength coupling-induced Fano resonances in symmetric terahertz metamaterials
,”
Phys. Status Solidi RRL
13
,
1900310
(
2019
).
28.
Q.
Wang
,
K.
Kuang
,
H.
Gao
,
S.
Chu
,
L.
Yu
, and
W.
Peng
, “
Electromagnetically induced transparency-like effect by dark-dark mode coupling
,”
Nanomaterials
11
,
1350
(
2021
).
29.
N.
Liu
,
H.
Guo
,
L.
Fu
,
S.
Kaiser
,
H.
Schweizer
, and
H.
Giessen
, “
Plasmon hybridization in stacked cut-wire metamaterials
,”
Adv. Mater.
19
,
3628
(
2007
).
30.
S.
Droulias
,
A.
Jain
,
T.
Koschny
, and
C. M.
Soukoulis
, “
Fundamentals of metasurface lasers based on resonant dark states
,”
Phys. Rev. B
96
,
155143
(
2017
).
31.
D.
Grischkowsky
,
S.
Keiding
,
M.
van Exter
, and
Ch.
Fattinger
, “
Far-infrared time-domain spectroscopy with terahertz beams of dielectrics and semiconductors
,”
J. Opt. Soc. Am. B
7
,
2006
2015
(
1990
).
32.
D.
Roy Chowdhury
,
X.
Su
,
Y.
Zeng
,
X.
Chen
,
A. J.
Taylor
, and
A.
Azad
, “
Excitation of dark plasmonic modes in symmetry broken terahertz metamaterials
,”
Opt. Express
22
,
19401
19410
(
2014
).
33.
S. Banerjee, C. S. Amith, D. Kumar, G. Damarla, A. K. Chaudhary, S. Goel, B. P. Pal, and D. Roy Chowdhury, “Ultra-thin subwavelength film sensing through the excitation of dark modes in THz metasurfaces,”
Opt. Commun
. 453, 124366 (2019).
34.
W.
Cao
,
R.
Singh
,
I. A. I.
Al-Naib
,
M.
He
,
A. J.
Taylor
, and
W.
Zhang
, “
Low-loss ultra-high-Q dark mode plasmonic Fano metamaterials
,”
Opt. Lett.
37
,
3366
3368
(
2012
).
35.
S.
Karmakar
,
D.
Kumar
,
B. P.
Pal
,
R. K.
Varshney
, and
D.
Roy Chowdhury
, “
Magnetic wire: Transverse magnetism in a one-dimensional plasmonic system
,”
Opt. Lett.
46
(
6
),
1365
1368
(
2021
).
36.
S.
Karmakar
,
D.
Kumar
,
R. K.
Varshney
, and
D.
Roy Chowdhury
, “
Lattice-induced plasmon hybridization in metamaterials
,”
Opt. Lett.
45
,
3386
3389
(
2020
).
You do not currently have access to this content.