Nanofotónica y Metamateriales con Nanoestructuras Metálicas y

Nanofotónica y Metamateriales con Nanoestructuras Metálicas y

IEM
Ins$tutode
Estructuradela
Materia
NanofotónicayMetamaterialesenelIEM
JoséA.SánchezGil
IEM
Ins$tutode
Estructuradela
Materia
Dpto.EspectroscopíaNuclear,VibracionalydeMediosDesordenados
EspectroscopíasdeSuperficieyFotónicadePlasmonesSuperficiales
JoseA.SánchezGil
&DiegoRomeroAbujetas
LuisS.Froufe-Pérez
RamónPaniagua
IEM
Ins$tutode
Estructuradela
Materia
¿Quéeslananofotónica?
1m=1.000.000.000nm
Cabezadealfiler:~1mm=1.000.000nm
Glóbulorojo:~7-8micras=7000-8000nm
Virus:24–300nm
Moléculadeagua:~0.275nm
LUZ
IEM
Ins$tutode
Estructuradela
Materia
¿Quéeslananofotónica?
ELECTROMAGNETISMO+MATERIACONDENSADA:
PROPAGACIÓN,CONFINAMIENTOEINTERACCIÓNRADIACIÓN-MATERIA
ENESCALASPORDEBAJODELALONG.DEONDA(λ)
IEM
Ins$tutode
Estructuradela
Materia
Fenomenología de interés en Nanofotónica
•  PlasmonesSuperficialesLocalizados
•  Metamateriales
•  LuzMagné$caendieléctricosdealtoíndice
•  Nanohilossemiconductores:Fotoluminiscencia
yabsorción
IEM
Ins$tutode
Estructuradela
Materia
METALESENELVISIBLE
TeoríadeDrudeparametales:elmodelodeelectroneslibres
¡SOLUCIONESCONFINADASENLAFRONTERAMETAL-DIELÉCTRICO!
PLASMONESSUPERFICIALES
IEM
Ins$tutode
Estructuradela
Materia
PLASMONESSUPERFICIALESLOCALIZADOS
(LOCALIZEDSURFACEPLASMONRESONANCES)
ELECTROSTÁTICA
TEORÍADEG.MIE(1908)
IEM
Ins$tutode
Estructuradela
Materia
¿PORQUÉNOSINTERESANLOSPLASMONES?
SURFACEPLASMONPOLARITONS
•  Sonmuysensiblesaloque$enenalrededor
oseencuentranporelcamino:
-deteccióndemoléculasaisladas
-estudionodestruc$vosdemuestras
•  Propiedadesdeconfinamientodelaluz
ydistanciasdepropagación(ondasquasi-2D),
buenoscandidatosparatransmisiónde
información.
LOCALIZEDSURFACEPLASMONS
•  Producengrandesintensificacionesdel
campo:
-aplicaciónenespectroscopías(SERS)
•  Producengrandesmodificacionesdela
densidadlocaldeestados:
-modificacióndelosprocesosdeemisión
deluz(inhibiciónointensificación)
•  Radiandeunamaneracontrolada:
-nanoantenna
IEM
Ins$tutode
Estructuradela
Materia
APLICACIONES
SURFACEPLASMONPOLARITONS
LOCALIZEDSURFACEPLASMONS
IEM
Ins$tutode
Estructuradela
Materia
ENTONCES…¿QUÉHACEMOSNOSOTROS,EXACTAMENTE?
• 
Estudiamoscómosecomportalaluzalinteractuarconunobjeto(nanométrico)
• 
Estudiamosquédiseñoeselmasadecuadoparaunpropósitoconcreto.
y…¿CÓMOLOHACEMOS?
• 
¡Esmuysencillo!
escribimoslasecuacionesquedescribenlatsicadelsistemay,
generalmente:
IEM
Ins$tutode
Estructuradela
Materia
Porejemplo,elsca$eringdeluzpornano-objetos:
Ecs.IntegralesdeSuperficie
EDP’s
GeometríaDiferencial
EcuacionesIntegrales
VariableCompleja
FuncionesEspeciales
max
CÁLCULONUMÉRICO
min
Giannini,Rodriguez-Oliveros
&Sánchez-Gil,Plasmonics(2010)
Gianninietal,JOSAA(2007)
IEM
Ins$tutode
Estructuradela
Materia
Rodriguez-Oliveros&Sánchez-Gil,Opt.Express(2011)
IEM
Ins$tutode
Estructuradela
Materia
Rodríguez-Oliveros&Sánchez-Gil,Opt.Express(2012)
IEM
Ins$tutode
Estructuradela
Materia
DELOTEÓRICO…
López-Tejeiraetal.NewJ.Phys.(2012)
…ALOAPLICADO
López-Tejeira,Paniagua-Domínguez
&Sánchez-Gil,ACSNano(2012)
IEM
Ins$tutode
Estructuradela
Materia
¿Quésonlosmetamateriales?
L
L << λ
IEM
Ins$tutode
Estructuradela
Materia
“Jugandoconlaspiezas”podemosobtener…
…cualquiervalordeRe(εeff)ydeRe(µeff)!!!
Re(µ)
Metamateriales“zurdos”
Re(ε)<0
Re(µ)>0
Re(ε)>0
Re(µ)>0
METAL
DIELÉCTRICO
Re(ε)
¿?
Re(ε)<0
Re(µ)<0
PLASMA
MAGNÉTICO
Re(ε)>0
Re(µ)<0
IEM
Ins$tutode
Estructuradela
Materia
Refracciónnega$va
Re(ε)>0
Re(µ)>0
Re(ε)<0
Re(µ)<0
IEM
Ins$tutode
Estructuradela
Materia
SRR
M-W
Re(µ)<0
Re(ε)<0
•Problemasdediseño:escaladohaciaelvisible,anchodebanda,disipación,
isotropía,…
•Problemasfundamentales:¿cómocalcularlaspropiedadesefec$vasdeunsistema
dado?¿cómogaran$zarquetengansen$dotsico?¿misistemaesrealmente
homogéneo?¿quéocurreenlasintercaras?¿cómotratamosladispersiónespacial,el
acoplamientomagnetoeléctricoolosgapsfotónicos?¿cómoop$mizarundiseñode
caraalaaplicación?
IEM
Ins$tutode
Estructuradela
Materia
Metamateriales“zurdos”eisótroposenelóp$co,
basadosennanoestructurascore-shell
Núcleo metálico:
Plasmon localizado
Recubrimiento dieléctrico:
Resonancia (Luz) Magnética
R.Paniagua-Domínguezetal.,New.J.Phys.(2011)
R.Paniagua-Domínguezetal.,Scien>ficReports(2013)
IEM
Ins$tutode
Estructuradela
Materia
Ag
Si
Rout
a
k
E
Rin
H
H E
k
ΓK
ΓM
ν = 235 THz
Dipole px
0
λ = 1.28 µm
|P|(TW/m2)
50
Dipole py
Negative Refraction
R.Paniagua-Domínguezetal.,New.J.Phys.(2011)
,Sci.Reports(2013)
Flat lensing
Abujetasetal.,J.Opt.(2015)
IEM
Ins$tutode
Estructuradela
Materia
Nanohilos Semiconductores
Resonancias Mie
Modos guíados
Luz confinada en la
nanoescala
Emisión (PL)
Absorción
IEM
Ins$tutode
Estructuradela
Materia
Semiconductor NW Photoluminescence/Absorption
•  Enhanced/Direc$onalPL
InPNWs:Fouriermicroscopy
(Grzelaetal,NanoLe~.2012)
vanDametal,NanoLe~.2015)
•  Enhanced/Direc$onalPL:
Analy$calmodel
(Paniaguaetal,Nanoscale2013)
•  Enhanced/Direc$onalAbsorp$on:
MieresonancesvsLeakymodes
(Grzegorzetal,NanoLe~.2014,ACSPhoton.2015)
IEM
Ins$tutode
Estructuradela
Materia
Nanofotónica
Semiconductor
NW (PL) Antenna
Emission
Metal
Nanorod
Fano LSP
Hybrid
(core-shell)
Metamaterials
NIMs
IEM
Ins$tutode
Estructuradela
Materia
Letter
pubs.acs.org/NanoLett
Directional and Polarized Emission from Nanowire Arrays
Dick van Dam,*,† Diego R. Abujetas,‡ Ramón Paniagua-Domínguez,‡ José A. Sánchez-Gil,‡
Erik P. A. M. Bakkers,†,§ Jos E. M. Haverkort,† and Jaime Gómez Rivas*,†,∥
†
Department of Applied Physics, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, The Netherlands
Instituto de Estructura de la Materia (IEM-CSIC), Consejo Superior de Investigaciones Científicas, Serrano 121, 28006, Madrid,
Spain
§
Kavli Institute of Nanoscience, Quantum Transport, Delft University of Technology, 2600 GA Delft, The Netherlands
∥
FOM Institute AMOLF, c/o Philips Research, High-Tech Campus 4, 5656 AE Eindhoven, The Netherlands
‡
S Supporting Information
*
ABSTRACT: Lighting applications require directional and
polarization control of the emitted light, which is currently
achieved by bulky optical components such as lenses, parabolic
mirrors, and polarizers. Ideally, this control would be achieved
without any external optics, but at the nanoscale, during the
generation of light. Semiconductor nanowires are promising
candidates for lighting devices due to their efficient light
outcoupling and synthesis flexibility. In this work, we
demonstrate a precise control of both the directionality and
the polarization of the nanowire array emission by changing
the nanowire diameter. We change the angular emission
pattern from a large-angle doughnut shape to a narrow-angle beaming along the nanowire axis. In addition, we amc00
tune| ACSJCA
the | JCA10.0.1465/W Unicode | research.3f (R3.6.i5 HF01:4227 | 2.0 alpha 39) 2014/03/19 08:04:00 | PROD-JCAVA | rq_3379248 |
polarization from unpolarized to either p- or s-polarized. Both the far-field emission pattern and its polarization are controlled by
the number and type of guided or leaky modes supported by the nanowire, which are determined by the nanowire diameter.
KEYWORDS: Nanowires, Fourier microscopy, polarization, emission, directionality
4/07/2014 14:24:27 | 8 | JCA-DEFAULT
Letter
pubs.acs.org/NanoLett
C
outcoupling has been theoretically18 and experimentally
ontrolling the polarization and directionality of the
1 Mode
Parity-Controlled Fano- and Lorentz-like Line Shapes Arising in
emission of nanosized light sources is of great importance
demonstrated.14,19 So far, no studyeither theoretically
or
1−4
in the engineering of light-emitting diodes (LEDs),
experimentallyof the interplay of both described mechanisms
2 Plasmonic Nanorods
Ultra
low-loss,
isotropic
optical
nanolasers,5,6 and applications
in quantum
optics such
as single
,†,‡
has been reported.
3 Niels Verellen,*
Fernando López-Tejeira,§ Ramón Paniagua-Domínguez,∥ Dries Vercruysse,‡,†
†
‡,†
photon sources.7−10 The bottom-up growth of semiconductor
In addition to directionality, control over the emission
4 Denitza Denkova, Liesbet Lagae,
Pol Van Dorpe,‡,† Victor V. Moshchalkov,† and José A. Sánchez-Gil∥
metamaterial
based on
nanowires (NWs) allows a negative-index
large design flexibility in parameters
polarization is important for many applications, such as solid†
SUBJECT AREAS:
5 INPAC and Department of Physics and Astronomy, KU Leuven, Celestijnenlaan 200 D, B-3001 Leuven, Belgium
such as nanowire
position,
size,
interwire
distance,
and
state
lighting,
sensing,
and
optical
communication.
Thin
‡
hybrid
metal-semiconductor
nanowires
METAMATERIALS
6 IMEC, Kapeldreef 75, B-3001 Leuven, Belgium
crystallographicNANOWIRES
orientation. This makes nanowires interesting
§
nanowires have the ability to emit strongly polarized
7 Departamento de Física de la Materia Condensada, Escuela de Ingeniería y Arquitectura, Universidad de Zaragoza, María de Luna 3,
R. Abujetas & J. A. Sánchez-Gil
2
SUB-WAVELENGTH
candidates
for theOPTICS
designR. Paniagua-Domı́nguez,
of nanosized D.
light
emitters and
8 E-50018 Zaragoza, Spain
light,20,21 which is a useful property for displays and sensing
11
NANOPHOTONICS
AND
∥
22
detectors.
Instituto de Estructura de la Materia (IEM-CSIC), Consejo Superior de Investigaciones Científicas, Serrano 121, E-28006 Madrid,
PLASMONICS
Instituto de Estructura de la Materia, Consejo Superior de Investigaciones Cientı́ficas,
121, 28006
Madrid,the
Spain. application
butSerrano
may
hinder
in quantum optics. 9 The
10 Spain
Wide-range control over the direction of the nanowire
nanowire polarization anisotropy has been first explained in the
Recently,
many fascinating
properties
predicted for
metamaterials (negative refraction, superlensing,
S Supporting Information
emission has notReceived
yet been
reported.
Previous
studies
have
11
*
electrostatic
limit
by the elongated shape of the nanowires
and
electromagnetic cloaking,…) were experimentally demonstrated. Unfortunately,
the best
achievements
2013
indicated the1 February
two main
mechanisms
that affect
thedomain,
nanowire
have no direct translation
to the optical
without being burdened by technological and conceptual
the highmetamaterials
refractive(NIM),
index
contrast with the environment,20 and
it
Accepted 12−14
difficulties. Of particular importance within the realm of optical negative-index
is the
12
ABSTRACT: We present the experimental observation of spectral
Recently,
the achieving
directional
emission
emission directionality.
6 March 2013
issue
of simultaneously
strong electric
and magnetic responses and low associated losses. Here,
has
later
been
described
in
terms
of
coupling
to
Mie
13
lines
of distinctly different shapes in the optical extinction cross-section
hybrid metal-semiconductor nanowires are proposed as building blocks of optical NIMs. The metamaterial
of thin InP nanowires
explained
by coupling
to leaky
Publishedhas been
22 index of refraction
of metallic nanorod antennas under near-normal plane wave
thus obtained,
highly isotropic
in the plane normal
to the nanowires,
presents a negative
resonances.
On top of that, the selection rules of the 14
band
15
21 March 2013
in the near-infrared,
with values
of the modify
real part well
below 21, and extremely low losses (an order of
15
illumination.
Surface plasmon resonances of odd mode parity present
These
modes
the
waveguide modes
in the nanowire.
21
magnitude better than present optical NIMs). Tunability of the system
allows
to
select
the
operating
range
in
structure of the emitting material also affect the polarization.
16
Fano interference in the scattering cross-section, resulting in
whole telecom causing
spectrum. The
is proven in configurations such as prisms and slabs, directly
direction of the nanowiretheemission,
andesign
antenna-like
17
asymmetric spectral lines. Contrarily, modes with even parity appear
observing negative refraction.
However, it is unknown how the polarization of the nanowire
Correspondence and
behavior.7,15,16
Identification of the relevant guided/leaky
18
as symmetric Lorentzian lines. Finite element simulations are used to
requests for materials
emission depends on the diameter, taking into account 19both
verify the experimental results. The emergence of either constructive or
nanowire should
modes
is important
tuning
the are
direction
of the
be addressed
to
he in
so called
metamaterials
artificial materials
in which the effective medium properties, usually exotic
20
destructive mode interference is explained with a semianalytical 1D line
17
and not naturally attainable, depend on the geometry of theirwaveguide
basic constituents,
rather than
on their
modes
and
selection rules.
J.A.S.-G. (j.sanchez@
far field emission.
The second
mechanism
was
associated
21
current model. This simple model directly explains the mode-parity
. Ranging
from
sub-diffraction resolution or spontaneous emission to extreme
chemical
composition that
csic.es)
Inhavethis
Letter
we discuss
the polarized and directional
many
exciting
and unexpected
phenomena
been achieved
or predicted
for
control over
the flowarrays
of light ,is
22
dependence of the Fano-like interference. Plasmonic nanorods are
with the emission directionality
of
NW
the
coupling
of
this new kind of materials. Although originally developed in electromagnetics, many of the ideas developed in this
23
widely used as half-wave optical dipole antennas. Our findings offer a
emission properties of semiconductor nanowire arrays, which
field in
have periodic
been successively
extended of
or adapted
to other ondulatory phenomena, such as acoustics, making it one
the emission to resonances
arrays
nanowires,
24
perspective and theoretical framework for operating these antennas at
of the most active in the engineering and physical sciences in the past few years.
which behave as quasi-two-dimensional
photonic
crystals.
The
25
higher-order modes.
Still, however, there are many open challenges in the field. Among them, the realization of a bulk isotropic
index
(NIM), withmay
negative
refraction and low losses in the optical domain . In general
photoluminescence excited negative
in one
ofmetamaterial
the nanowires
couple
Received: March 23, 2015
26
KEYWORDS: Nanoantenna, surface plasmon resonance, Fano resonance, interference, plasmonics
terms, the major issue when trying to achieve such a goal is obtaining a strong diamagnetic response of the
constituents,
enough
to
lead
to
an
effective
negative
permeability.
Probably
as
a
consequence
of
the
success
of
the
to Bloch modes supported by the periodic structure and couple
Revised:
May 21, 2015
original designs operating in the microwave regime, many efforts were made to adapt them to increasingly higher
2015
out to free space in certain
This . directional
Apart from some inheritedPublished:
from the original June
designs,4,
such
as anisofrequencies,directions.
mainly by miniaturization
the shape, size, and dielectric environment by using a variety of
etallic nanorods are exploited as biological imaging
27
T
1,2
3,4
5
6,7
8,9
8,9
tropy, many drawbacks were found in doing so, mainly related to the different behaviour of metals at optical
frequencies, such as saturation of the magnetic response10 or high losses associated to ohmic currents. As a
consequence,
completely
different Society
strategies were studied to4557
obtain artificial magnetism11,12, as those based in
© 2015 American
Chemical
displacement currents appearing in nanoparticle clusters due to coupling between structures13. However, some of
the most successful were those which attempted to obtain it from natural magnetic resonant modes in high
permittivity dielectrics, leading to low-loss magnetic materials14–18. Secondary structures or particular arrangements were needed to provide the additional electrical response, necessary to obtain doubly negative index of
refraction19–21. Thus far, the maximum theoretical figure of merit (f.o.m 5 2Re(neff)/Im(neff)) reported is of the
order of f.o.m., 2522–24 for metamaterials based on canonical fishnet designs; their dimensions, however, are in
the very limit of validity of the effective medium description, and isotropy was not proven (see25 for a review on
this topic).
In this work, we propose a structure that, combining electric and magnetic responses, can be used as the basic
building block for extremely low-loss (f.o.m., 200) isotropic two-dimensional metamaterials in the near-infrared, with simultaneously negative permittivity ( ) and permeability (m) at optical frequencies. Such structure is a
core-shell nanowire (NW) of circular cross section. Noble metals such as silver or gold can be employed to build
the core, and high permittivity semiconductors, such as silicon or germanium, to build the shell. Artificial
magnetism of the effective medium is achieved by exciting the lowest order Mie-like magnetic resonance in
28
M
probes and widely used as generic plasmonic dipole
methods.12,13,25−27 Despite this large interest in nanorods, only
very few reportsall theoreticaladdress the scattering
behavior with a focus on the spectral line shape.28−30
Plasmon resonance, as a wave phenomenon, is expected to
present interference characteristics. The wave nature of
propagating surface plasmon polaritons (SPPs) was elegantly
demonstrated with a Young’s double slit experiment.31 For
localized surface plasmon resonances, the interference of
spectrally overlapping and coupled modes is well-recognized
to affect the scattering behavior of the nanostructure under
investigation.32,33 In particular, the interference of a broad
background continuum state with spectrally sharp higher-order
resonances, as schematically illustrated in Figure 1a, can lead to
a spectral response with asymmetric Fano-like line shapes in a
variety of nanoparticle configurations such as nanosphere
clusters,34 asymmetric dolmen-like nanorod arrangements,35,36
Paramásinformación:JoséA.SánchezGil.
[email protected],2ªPlanta.Extensión942219
29 antennas operating at optical and near-infrared frequencies,
DOI: 10.1021/acs.nanolett.5b01135
Nano Lett. 2015, 15, 4557−4563
30 forming an analogue to classical half-wave dipole antennas.
31
32
33
34
35
36
37
38
39
40
41
SCIENTIFIC REPORTS | 3 : 1507 | DOI: 10.1038/srep01507
1
42
Nanorod antennas are an excellent tool for the manipulation of
a variety of nanoscale light−matter interactions.1,2 They form
the building blocks for Yagi-Uda antennas which allow
directional control of light,3−6 or they can act as active optical
antennas for photodetection by generating hot electrons.7
Recently, it was demonstrated how plasmonic nanorods can be
used to efficiently convert the radiation of quantum emitters
into novel multipolar sources of photons owing to the higherorder localized surface plasmon resonances (LSPRs) supported
by these antennas.8,9
The fundamental dipole and higher-order antenna modes
have been extensively studied experimentally using optical
10−15
50
51
52
53
54
55
56
57
58
59
60
61
62
63 f1
64
65
66