Plasmonics

- Merging Photonics with Nanotechnology –

ASEPS 2013, Chiba

Stefan Maier

Experimental Solid State Group / Centre for Plasmonics & Metamaterials

Physics Department, Imperial College London

S.Maier@imperial.ac.uk

http://www3.imperial.ac.uk/people/s.maier http://www3.imperial.ac.uk/plasmonmeta

Imperial College London

2

Academic FacultiesNatural Sciences

Engineering

Medicine

Business School

established in 1907via merger of Royal School of Mines,

Royal College of Science, and

City and Guilds College

Astrophysics Photonics

Condensed Matter Theory Plasma Physics

Experimental Solid State Physics Quantum Optics & Laser Science

High Energy Physics Space and Atmospheric Physics

Theoretical Physics

The Great Exhibition 1851

Nanotechnology

3

Planet

Care

Composites

Characterisation

Eco-processing

Catalysts

Fuel

Cells

Manufacturing

Methods

Photovoltaics

& Solar Cells

Simulation

Materials

Detectors

Information

Technology

MEMS &

Vacuum

Electronics

Materials Growth

and Synthesis

Spintronics &

Superconductors

Optoelectronics

Photonics

Devices and

Sensors

Quantum Computing

and Cryptography

Modelling &

Simulation

Scan-probes

Novel

Magnetic &

Diamond

Materials

Bio-nano

Sensors

Bio-compatible

Nanomaterials

Advanced

Medical Imaging

Bio-Nano

Particles

Technologies

for Diagnosis

Self-assembled

Bio-structures

Drug Screening

Technologies

Molecular

Simulation

Lab-on-a-chip

& Screening

Degenerative

Disease

Studies

Healthcare

Size in photonics: macroscopic, microscopic

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Photonics is all

around us)

Controlling light below the wavelength scale

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CMOS Nanoelectronics

Light difficult to control below

the wavelength scale

sub-50 nm lengthscale

hitting interconnect bottleneck

Integrated Photonics

D

fq

λ22.1Airy =

M. Brongersma et al, Science 2010

From bulk to nanosized metals

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bulk and thin film nanostructures

Plasmonics in a nutshell

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10 nm

5 µm

Nanoplasmonics: the new science of light

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Fundamentals of Light/Matter Coupling

New Toolkit for Scientific Investigations

Technologies involving Light: smaller, faster,

cheaper

New horizons:quantum effects

active nanodevicesmulti-spectral response

Optics meets Nanotechnology

50 nm

100nm

NanofabricationNanofabrication

Nanostructured metalsNanostructured metals

Nanostructured light fieldsNanostructured light fields

Nanoplasmonic probes

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Optical readout

Light concentration

Nano Letters 12, 780 (2012)

Optics Letters 35, 3988 (2010)

ACS Nano 6, 3537 (2012) Small 6, 2498 (2010)

Investigating dimer modes via graphene

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Utilize local strain in graphene for hot spot characterization

via concofal Raman measurements:

graphene as a local near-field probe linking near-field with

topography

Heeg et al, Nano Letters 13, 301 (2013)

Red-shifts + peak splitting of 2D peak: hydrostatic strain (~0.8%)

corresponding to single hotspots

Current research strands in plasmonics

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Active nanophotonics

Transformation OpticsNanoantennas Quantum Plasmonics

THz plasmonic sensorsEmission engineering

Nanoantenna fundamentals and applications

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Nanoantennas

Plasmonic nanoantennasDesigner properties via Fano, log periodic and

hybrid photonic resonances, mode investigation,

applications in sensing, metrology and energy

ACS Nano 7, 669 (2013)

Nano Letters 13, 301 (2013)

Nature Communications 3, 1108 (2012)

Nano Letters 12, 4997 (2012)

Nano Letters 12, 2101 (2012)

ACS Nano 6, 1830 (2012)

Nano Letters 12, 1683 (2012)

Antonio Fernández-DomínguezHeykel Aouani Miguel Navarro-Cía Themis Sidiropoulos Dangyuan Lei Markus Schmidt

Roberto Fernández-García Aeneas WienerNic Hylton Vincenzo GianniniYannick Sonnefraud Yan Francescato

Hot spot imaging

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Nano Letters 12, 1683 (2012)

Nano Letters 11, 1323 (2011)

STEM

EELS

EDS

Nanoantenna scattering vs absorption

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Absorption losses: Drude relaxation

and interband transitions

Radiative losses: optical nanoantenna

Plasmon decay channels:

Giannini et al, Chemical Reviews 111, 3888 (2011)

Plasmonics for improved photovoltaics

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Atwater and Polman, Nature Materials 9, 205 (2010)

Ferry et al, Advanced Materials 22, 4794 (2010)

Opportunities arising from plasmonic light concentration: thinner cells (> 100 µm to ~ 1µm)

reduced cost

less depletion of naturally occurring stocks

use of materials with low minority carrier

diffusion lengths

more efficient // higher open-circuit voltage

ease of integration into processing work

flows

optically thick, physically thin

Yu et al, PNAS 107, 17491 (2010)

Control over radiative properties (I): materials

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Knight et al, Nano Letters 12, 6000 (2012)

Majority of nanoantenna work: Au, Ag

More recent: Al, tunability UV to visible

Trade-off far-field scattering

vs absorption favourable for Al!

Mie theory: Absorption/Scattering (R, λ)

Application in plasmon-enhanced PV

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Prog. Photovolt: Res. Appl. 21, 109 (2013)

Optics Express 19, A888 (2011)

GaAs Cell

R = 80 nm and Ʌ = 400 nm

Photocurrent map

Particle absorption map

Linking full-field EM simulations with charge

carrier diffusion modelling

Plasmon-enhanced thin-film GaAs photodiodes

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200 nm pitch

Control over radiative properties (II): Fano modes

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Sub/super radiance Fano modes

Giannini et al, Small 6, 2498 (2010)

Highly directed scattering via a Fano resonance

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Optical Yagi Uda anteannas

Curto et al, Science 329, 930 (2010)

V antenna for side scattering

100 nm

Single particle forward scattering via

electric/magnetic dipole interferences:

Miroshnichenko, ACS Nano 6, 5489 (2012)

Side scattering in bimetallic antennas:

Shegai, Nat Comm 2, 481 (2011)

Directional scattering at the Fano resonance

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Explanation via a dipolar model

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cos((∆ϕ-kd)/2) cos((∆ϕ+kd)/2)

650nm 730nm

dd

dipoles of equal strength,

π phase difference

Antennas for surface enhanced spectroscopies

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Small 6, 2498 (2010)

Fluorescence enhancement

Change in decay rates

Enhanced absorption

Improved directionality

Enhancement factors between 10

and 1000

SERS and SEIRA

SERS electromagnetic

enhancement ~ Eloc4, between

105 and 1010

SEIRA electromagnetic

enhancement ~ Eloc2, between

104 and 105

PRL 101, 157403 (2008)J Phys Cond Matter 14, R597 (2002)

Towards a common sensing platform

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Challenge:

Narrow plasmonic resonances

Development of a suitable platform for

multispectral surface-enhanced sensing of

trace molecules on the same chip:

fluorescent, SERS, SEIRA, THz (?)

Broadband response via log periodic design

25ACS Nano 6, 3537 (2012)

1

2

3

5

4

Connection between teeth

provides central hotspot for

all resonance frequencies

A multi-sensing platform

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Surface enhanced fluorescence

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Gold film

reference

x cut

x

y

� x5 fluorescence gain (670 nm)

Surface enhanced Raman

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� 104 SERS gain (780 nm)

SERS spectrum

Surface enhanced infrared absorption

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� 1.1 x 104 inf. absorption gain (3000 nm)

Nanoantenna fundamentals and applications

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Nanoantennas

ACS Nano 7, 669 (2013)

Nano Letters 13, 301 (2013)

Nature Communications 3, 1108 (2012)

Nano Letters 12, 4997 (2012)

Nano Letters 12, 2101 (2012)

ACS Nano 6, 1830 (2012)

Nano Letters 12, 1683 (2012)

Electron energy loss spectroscopy for

high resolution spatial mode imaging

Fano resonances and directional

scattering

Logperidic design and broadband

surface enhanced spectroscopies and

nonlinear nanophotonics

Field is spanning physics, materials

science, and electrical engineering:

fruitful breaking of boundaries

Outline

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Transformation Optics

Transformation Optics Singularities and non-localities

Science 337, 1072 (2012)

Science 337, 549 (2012)

Advanced Materials 24, OP226 (2012)

PRL 108, 023901 (2012)

PRL 108, 106802 (2012)

Nano Letters 12, 5946 (2012) Antonio Fernández-Domínguez Stephen HanhamDangyuan Lei

Cavity design using transformation optics

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Challenge: Nanoscale superfocusing

structure with a broadband response

Problem: Small plasmonic cavities

are usually inherently narrow-band

But: Planar interfaces supporting

propagating SPPs show a

broadband response

Aubry et al, Nano Letters 10, 2574 (2010)

Energy density scales

as square of compression!

Singularity removes quantization

of resonance frequencies

0 20 40 60 80 1000

2

4

6

8ω=c k

x

λ=337 nm ; ε1= -1

ω (

10

15 s

-1)

kx (µm

-1)

JB Pendry et al, Science 312 1780-2 (2006)

A powerful approach giving physical insight

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PRL 105, 233901 (2010)ACS Nano 5, 3293 (2011)

PRB 82, 205109 (2010) ACS Nano 5, 597 (2011)

PRL 105, 266807 (2010) PRL 108, 023901 (2012) PRL 108, 106802 (2012)

Broadband light harvesters

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Science 337, 549 (2012)

increasing

overlap

Advanced Materials 24, OP226 (2012)

Particle-on-film gap modes: nonlocal effects

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Science 337, 1072 (2012)

NJP 12, 093030 (2010)

see Science paper supplementary information

Outline

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Transformation Optics

Science 337, 1072 (2012)

Science 337, 549 (2012)

Advanced Materials 24, OP226 (2012)

PRL 108, 023901 (2012)

PRL 108, 106802 (2012)

Nano Letters 12, 5946 (2012)

Analytical formulas for relevant

2D and 3D geometries of touching

or closely separated wires and

particles

Study of nonlocal effects

Transformation optics

as a framework for

broadband cavity design

Singularities are the

key to broadband

superfocusing

Collaborators

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Joel Yang

Michel Bosman

Boris Luk’yanchuk

Jinghua Teng

Anatoly Zayats

Jiri Homola Lothar Wondraczek

Virginie Nazabal

Stephanie Reich

David Smith

Ned Ekins-Daukes

Paul Stavrinou

Donal Bradley

Lesley Cohen

Minghui Hong

Shuang Zhang

Richard Haglund

Francisco García-Vidal

Juan José Sáenz

Pol Van Dorpe

Javier Aizpurua

Dang Yuan Lei

Peter Nordlander

Naomi Halas

Weili Zhang

Markus Schmidt

Joshua Caldwell

John Pendry

Ortwin Hess

Rupert Oulton

Myungshik Kim

Nanoplasmonics @ Imperial College London

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Active nanophotonics

Transformation OpticsNanoantennas Quantum Plasmonics

THz plasmonic sensorsEmission engineering