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See discussions, stats, and author profiles for this publication at: https://www.researchgate.net/publication/273771287 slides-SHG enhancement via Fano resonances Data March 2015 CITATIONS READS 0 20 1 author: Mehmet Emre Tasgin Hacettepe

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See discussions, stats, and author profiles for this publication at: https://www.researchgate.net/publication/273771287

slides-SHG enhancement via Fano resonances

Data · March 2015

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1 author: Some of the authors of this publication are also working on these related projects: Novel methods for enhanced Raman spectroscopy View project Design and fabrication of nonlinear plasmonic converters for enhanced infrared efficiency in Si solar cells View project Mehmet Emre Tasgin Hacettepe University

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SLIDE 2

Enhancement/suppression of SHG via Fano resonances

1

SLIDE 3

Standard EIT (active medium)

2

microwave introduces 2 paths active medium

SLIDE 4

Plasmonic EIT (passive medium ; Fano resonances)

2

Gold Nanoantenna hot spot

I = 105 ×|E0|2

E(t)=E0 e-iωt

SLIDE 5

Plasmonic EIT (passive medium ; Fano resonances)

2

plasmon polarization (hot-spot) Quantum Dot

I = 105 ×|E0|2

E(t)=E0 e-iωt

put a 𝒆 = 𝒇𝒔 QD dipole-moment

interacts

Gold Nanoantenna

SLIDE 6

Plasmonic EIT (passive medium ; Fano resonances)

3

Quantum Dot

I = 105 ×|E0|2

E(t)=E0 e-iωt

put a

γeg=109 Hz

MNP QD

γMNP=1014 Hz

|e |e> |g> |g>

γMNP

coupled

Gold Nanoantenna

schematically

SLIDE 7

Plasmonic EIT (passive medium ; Fano resonances)

3

[1] C. L. G. Alzar et al., Am. J. Phys. 70, 37 (2002). Quantum Dot

I = 105 ×|E0|2

E(t)=E0 e-iωt

put a Gold Nanoantenna

MNP

γMNP=1014 Hz

γMNP

hybridization

SLIDE 8

Plasmonic EIT (passive medium ; Fano resonances)

3

Quantum Dot

I = 105 ×|E0|2

E(t)=E0 e-iωt

put a Gold Nanoantenna

SLIDE 9

|e> |g>

ћωeg

q

Classical Oscillator Quantum Oscillator

F(t)=Fe

iωt (Drive)

ρeg

Quantum Dot Gold Nanoantenna

a) b)

[2] M. Emre Taşgın, Nanoscale 5, 8616 (2013).

Model

coupled a simple model life-time of plasmon extends

[2]

4

SLIDE 10

[2] M. Emre Taşgın, Nanoscale 5, 8616 (2013). [3] Noginov et al., Nature 460,1110 (2009).

Spaser (Surface Plasmon Amplification by stimulated emission of radiation )

MNP moleküller ile etkilişiyor

5

[3]

SLIDE 11

[2] M. Emre Taşgın, Nanoscale 5, 8616 (2013). [3] Noginov et al., Nature 460,1110 (2009).

Spaser (Surface Plasmon Amplification by stimulated emission of radiation )

narrowing in the emission band of MNP MNP moleküller ile etkilişiyor explains

5

life-time of plasmon extends [3] [3] [2]

SLIDE 12

Enhancing/Suppressing Nonlinear Response

[4] D. Turkpence, Gursoy B. Akguc, Alpan Bek, M. E. Tasgin, J. Opt. 16, 105009 (2014). MNP cross-section QD at the hot-spot

ω 2ω ? ?

6

SLIDE 13

Enhancing/Suppressing Nonlinear Response

[4] D. Turkpence, Gursoy B. Akguc, Alpan Bek, M. E. Tasgin, J. Opt. 16, 105009 (2014). MNP cross-section

7

SLIDE 14

[4] D. Turkpence, Gursoy B. Akguc, Alpan Bek, M. E. Tasgin, J. Opt. 16, 105009 (2014). Result: |𝛽2|2 = 2ω plasmon

ccupasion

|𝛽1|2 = ω plasmon

ccupasion

ωeg

γ1 γ2 decay rate of ω1-mode decay rate of ω2-mode χ(2) = nonlinear susceptibility

f2 = MNP – QD coupling Result

8

SLIDE 15

SHG Enhancement

Result:

f2 = MNP – QD coupling

choose ωeg such that

imag part 𝑗(𝜕2 − 2𝜕)

9

SLIDE 16

SHG Enhancement

Result:

f2 = MNP – QD coupling

choose ωeg such that

imag part 𝑗(𝜕2 − 2𝜕)

9

SHG enhancement factor

SLIDE 17

SHG Enhancement

9

SHG enhancement factor Referees asked What about retardation effects?

SLIDE 18

SHG from single MNP (4 nm2)

MNPBEM Simulation (a) single SHG cross-section (nm2)

λsh=λexc/2 (nm)

coupled SHG cross-section (nm2) (b)

λsh=λexc/2 (nm)

MNPBEM Simulation

QD Fano resonance induces 100 times SHG enhancement (500 nm2)

3D Boundary Element Method Simulations (exact solutions)

10

SLIDE 19

no one explained as

So what?

11

SHG enhancement due to Fano resonances already shown experimentally already shown via 3D simulations so what is the point here? OK, but what this explanation worth ?

SLIDE 20

1 MNP and 2 QDs

107 times SHG enhancement!!

[8] M. E. Tasgin, “Divergent nonlinear optical response of three resonator system via

Fano resonances” arXiv:1404.3901

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