NANOSCALE SPECTROSCOPY WITH

OPTICAL ANTENNAS

e - h +

hn

The Institute of Optics, University of Rochester, Rochester, NY, 14627.

Lukas Novotny

DOE, AFOSR, NSFwww.nano-optics.org

e - h +

hn

antenna

hnDOE, AFOSR, NSFwww.nano-optics.org

NANOSCALE SPECTROSCOPY WITH

OPTICAL ANTENNAS

ANTENNA-BASED INTERACTIONS

e - h+

photovoltaics

hn

e - h+

hn

LED

h+

hn hn

e -

spectroscopy

Nature 455, 887 (2008).

ANTENNA

A DEVICE TO CATCH ELECTROMAGNETIC WAVES

Before 1900: Aerial

First written usage: Manuel Rodriguez Garcia (French Patent, 1900)

OPTICAL ANTENNA

A DEVICE TO CONVERT OPTICAL RADIATION

INTO LOCALIZED ENERGY, AND VICE VERSA.

OPTICAL ANTENNAS IN NATURE

PHOTOSYNTHESIS: COLLECTIVE RESPONSE OF CHLOROPHYLL MOLECULES

PROBLEM STATEMENT

(molecule, ion, quantum dot, ..)

receiver/transmitter

antenna

radiation

-> coupled system of 3 entities

OPTICAL HALF-WAVE ANTENNA

220nm

l / 5.6 !~ l / 2

EFFECTIVE WAVELENGTH SCALING

PRL 98, 266802 (2007)800

220

L = 110nm

OPTICAL YAGI-UDA ANTENNA

QuickTime™ and aTIFF (Uncompressed) decompressor

are needed to see this picture.

T. Taminiau et al., Opt. Exp. 16, 16858 (2008)

NANOSCALE CHEMICAL IMAGING

?

Spatial Resolution

Ch

em

ica

l In

form

ati

on

1 nm 1 m 1mm

low

ato

mic

mo

lecu

larNMR

- IR

-Raman

STM

ElectronMicroscopy

Ion microscopy

X-Rays

DielectricAnalysis

S. Stranick, NIST

EXAMPLES

ASA Tablet: Toothpaste:

Source: WITec

NEAR-FIELD OPTICAL SPECTROSCOPY

Ultramicroscopy 71, 21 (1998).

The History of Near-field Optics, Rep. Prog. Opt. (2007).

BOTTOM-UP SYNTHESIS

OF OPTICAL ANTENNAS

P. Bharadwaj

PRL 90, 95503 (2003)

w N

wowNwo-+

NEAR-FIELD RAMAN

SCATTERING

N. AndersonA. Hartschuh G. Cancado

3D CONFINEMENT OF SIGNAL

0 20 40 60

1

2

3

4

z (nm)

sig

na

l en

ha

nce

me

nt

PRL 90, 95503 (2003)

LOCAL ENVIRONMENT

PRL 90, 95503 (2003)

Topography Raman scattering

M G’G

RBM (259cm-1)

(n,m) = (8,5) : dt ~ 0.9nmTint = 210ms / pixel1.0 um x 1.0 um

D IFM (835cm-1)

LOCALIZATION OF DEFECTS

JACS 127, 2533 (2005)

STRUCTURAL DEFECTS

Topography: Confocal Raman:

Structural Variations (defects, branching, .. ) hidden in confocal imaging !

Near-field Raman:

Nano Lett. 6, 744 (2006)

SERPENTINE NANOTUBES(E. Joselevich)

NEAR-FIELD RAMAN IMAGING

OF SERPENTINE NANOTUBES

Topography : Confocal Raman :

n = 1594cm-1

Near-field Raman :

n = 1594cm-1

- strain

MEASURING LOCAL PROPERTIES

- environment

- defects

- local potential

- dopants

100nm

Gt1

t2

t3

t4

t5

t6

t7

t8

t9

t10

0 500 1000 1500 2000 2500

m

m

m

m

m

sc

sc

sc

t1

t2

t3

t4

t5

t6

t7

t8

t9

t10

sc

sc

TUBE-TUBE TRANSITIONS

Nano Lett. 7, 577 (2007)

160 180 200 220 240 260 280 300

Raman shift (cm-1)

RBM 191 (M):

(n,m) = (12,6)

dt ~ 1.25nm

RBM 251 (SC):

(n,m) = (10,3)

dt ~ 0.94nm

Nano Lett. 7, 577 (2007)

ENHANCING LIGHT EMISSION

ANTENNA-ENHANCED

FLUORESCENCE

SiO2

Au

molecule

PRL 96, 113002 (2006)

SINGLE MOLECULE FLUORESCENCE RATES

qa

without Au particle :

PRL 96, 113002 (2006)

with Au particle antenna:

ANTENNA-ENHANCED

FLUORESCENCE

QUANTUM YIELD

energy transfer + intrinsic

Fluorophore Nanotube

Nano Lett. 5, 2310 (2006)

Ca2+ PUMPS IN RED BLOOD

CELL MEMBRANES

Ca2+ ATPase (4 genes -> 4 isoforms)

Alzheimers, hypertension, diabetes, ..

Role of specific isoforms ?

Spatial organization ?

Impact on pathologies ?

IMAGING OF SINGLE Ca+ ION CHANNEL

PROTEINS IN ERYTHROCYTE MEMBRANES

C. Hoeppener

IMAGING OF SINGLE Ca+ ION CHANNEL

PROTEINS IN ERYTHROCYTE MEMBRANES

C. Hoeppener

Nano Lett. 8, 642 (2008)

NONLINEAR RESPONSE

NONLINEAR RESPONSE(780nm + 1160nm laser pulses)

350 400 450 500 550 600 650 700

l (nm)

ph

oto

n c

ou

nts

(a

rb. u

nits)

S. PalombaM. BeversluisA. Bouhelier M. Danckwerts

FOUR-WAVE MIXING DISTANCE DEPENDENCE

PRL 98, 026104 (2007)

*

CONCLUSIONS

Antenna-coupled light-matter interactions

- Spectroscopy with spatial resolution ~10 nm

- Opportunities for LEDs, photovoltaics

- Nonlinear plasmonics

www.nano-optics.org

Thanks: Ado Jorio, Steve Cronin, Todd Krauss, Ernesto Joselevich, Lewis Rothberg,

Alex Noy, Shanlin Pan, Brian Holmberg, Barbara Schirmer, Ryan Beams,

Brian McIntyre,