L. Coolen, C.Schwob, A. MaîtreInstitut des Nanosciences de Paris (Paris)

Engineering Emission Properties Engineering Emission Properties

with Plasmonic Structureswith Plasmonic Structures

B.Habert, F. Bigourdan, F. Marquier, JJ. GreffetLaboratoire Charles Fabry de ’Institut d’Optique, Palaiseau

(France)

C.Belacel, S.Michaelis De Vasconcellos, X.Lafosse, P. Senellart

Laboratoire de Photonique et Nanostructure (Marcoussis)

C. Javeaux, B. Dubertret Ecole Supérieure de Physique et de Chimie Industrielles (Paris)

2

Plasmonic Gold NanoshellPlasmonic Gold Nanoshell

Dielectric

Gold

Emitter ~ 100nm

~ 10nm

3

Resonance of a NanoshellResonance of a Nanoshell

+++++

+

--

--

-

Restoring force = resonance

4

Tunable ResonanceTunable Resonance

5

Emission EnhancementEmission Enhancement

Small mode volume: high Local Density of Optical States

6

Radiative Purcell FactorRadiative Purcell Factor

7

Excitation Excitation EnhancementEnhancement

Ratio =

8

SNR SNR EnhancementEnhancement

9

Fabrication + Quality Fabrication + Quality FactorFactor

10

Plasmonic Patch Antenna Plasmonic Patch Antenna

Purcell 1946Spontaneous emission depends on Local Density of States

Small mode volume High density of state Fast decayStructure geometry radiation pattern

|EZ |

+ + + - - - + + + - - - - - - + + + - - - + + +

11

Fabrication ProcessFabrication Process

Colloidal Quantum DotsB. Dubertret (ESPCI)Optical In-Situ Lithography

P. Senellart (LPN)

12

Measurement of Decay Measurement of Decay RateRate

Start-Stop Lifetime measurementA. Maître (INSP)

13

Measurement of DirectivityMeasurement of Directivity

θr

High NA microscope objective

Back-Focal Plane

Image of the back focal plane

14

ConclusionsConclusions

• Small volumes lead to decay rate enhancement

• Coupling far field to the emitter increases fluorescence efficiency

• Structure geometry for tuning of radiation pattern

15

PerspectivesPerspectives

• Single Quantum Dots

• Improving radiative efficiency

*Photon

Plasmonic antenna modeQuenching (heat)

coupled to far-field

absorbed

16

Spontaneous Emission or Spontaneous Emission or Quenching?Quenching?

*Photon (vacuum mode)

Plasmon (surface mode)

Quenching (heat)

coupled to far-fieldabsorbed

17

Controlling Spontaneous Controlling Spontaneous Emission Emission

| EZ |

18

Log10 (Purcell factor)

Dis

k d

iam

ete

r (u

m)

dielectric thickness (um)

30 nm thickness

19

Controlling DirectivityControlling Directivity

+ + + - - - + + + - - - + + + - - - + + + - - - + + + - - -

Standing wave for the current distribution in the metalThe structure radiates as an antenna

Radiation patterns controlled by the shape/size of the antenna

20

Without surface scattering

With surface scatteringd_scatt = 2nm

Radiation EfficiencyRadiation Efficiency

21

Plasmonic antenna as a Plasmonic antenna as a solutionsolution

Alberto G. Curto, et al.Science 329, 930 (2010)

Sergei Kuhn, et al.PRL 97, 017402 (2006)