Transcript Plasmonic Gold Nanoshell - Weizmann Institute of Science

Engineering Emission Properties
with Plasmonic Structures
B.Habert, F. Bigourdan, F. Marquier, JJ. Greffet
Laboratoire Charles Fabry de ’Institut d’Optique, Palaiseau (France)
C.Belacel, S.Michaelis De Vasconcellos,
X.Lafosse, P. Senellart
Laboratoire de Photonique et Nanostructure (Marcoussis)
L. Coolen, C.Schwob, A. Maître
Institut des Nanosciences de Paris (Paris)
C. Javeaux, B. Dubertret
Ecole Supérieure de Physique et de Chimie Industrielles (Paris)
Plasmonic Gold Nanoshell
Gold
Dielectric
Emitter
~ 100nm
~ 10nm
2
Resonance of a Nanoshell
-
+
+
+
+
+
+
Restoring force = resonance
3
Tunable Resonance
4
Emission Enhancement
Small mode volume: high Local
Density of Optical States
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Radiative Purcell Factor
6
Excitation Enhancement
Ratio =
7
SNR Enhancement
8
Fabrication + Quality Factor
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Plasmonic Patch Antenna
Purcell 1946
Spontaneous
emission depends on
Local Density of
States
|EZ |
+++
- - -
+++
- - -
- - -
+++
- - -
+ ++
Small mode volume  High density of state  Fast decay
Structure geometry  radiation pattern
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Fabrication Process
Optical In-Situ Lithography
P. Senellart (LPN)
Colloidal Quantum Dots
B. Dubertret (ESPCI)
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Measurement of Decay Rate
Start-Stop Lifetime measurement
A. Maître (INSP)
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Measurement of Directivity
θ
r
High NA
Backmicroscope Focal
objective
Plane
Image of the back focal
plane
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Conclusions
• Small volumes lead to decay rate enhancement
• Coupling far field to the emitter increases
fluorescence efficiency
• Structure geometry for tuning of radiation pattern
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Perspectives
• Single Quantum Dots
• Improving radiative
efficiency
*
Photon
Plasmonic antenna
mode
Quenching
(heat)
coupled to
far-field
absorbed
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Spontaneous Emission or Quenching?
*
Photon (vacuum mode)
Plasmon (surface mode)
Quenching (heat)
coupled
to far-field
absorbed
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Controlling Spontaneous Emission
| EZ |
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Log10 (Purcell factor)
Disk diameter (um)
30 nm thickness
dielectric thickness (um)
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Controlling Directivity
+++ - - - +++
++
- - - +++ - - - -
- - - +
+ ++ -
Standing wave for the
current distribution in the
metal
The structure radiates as an
antenna
Radiation patterns controlled
by the shape/size of the
antenna
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Radiation Efficiency
Without surface
scattering
With surface scattering
d_scatt = 2nm
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Plasmonic antenna as a solution
Alberto G. Curto, et al.
Science 329, 930
(2010)
Sergei Kuhn, et al.
PRL 97, 017402 (2006)
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