slides-SHG enhancement via Fano resonances Data March 2015 - PDF document

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 University 79 PUBLICATIONS 282 CITATIONS SEE PROFILE 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 All content following this page was uploaded by Mehmet Emre Tasgin on 20 March 2015. The user has requested enhancement of the downloaded file.

1 Enhancement/suppression of SHG via Fano resonances

2 Standard EIT (active medium) microwave introduces 2 paths active medium

2 Plasmonic EIT (passive medium ; Fano resonances) Gold Nanoantenna E(t)=E 0 e -i ω t hot spot I = 10 5 × | E 0 | 2

2 Plasmonic EIT (passive medium ; Fano resonances) Gold Nanoantenna E(t)=E 0 e -i ω t plasmon polarization (hot-spot) put a Quantum interacts Dot I = 10 5 × | E 0 | 2 𝒆 = 𝒇𝒔 QD dipole-moment

3 Plasmonic EIT (passive medium ; Fano resonances) Gold Nanoantenna E(t)=E 0 e -i ω t schematically |e> |e γ MNP put a coupled Quantum Dot |g> |g> I = 10 5 × | E 0 | 2 MNP QD γ MNP =10 14 Hz γ eg =10 9 Hz

3 Plasmonic EIT (passive medium ; Fano resonances) Gold Nanoantenna E(t)=E 0 e -i ω t γ MNP hybridization put a Quantum Dot I = 10 5 × | E 0 | 2 MNP γ MNP =10 14 Hz [1] C. L. G. Alzar et al. , Am. J. Phys. 70, 37 (2002).

3 Plasmonic EIT (passive medium ; Fano resonances) Gold Nanoantenna E(t)=E 0 e -i ω t put a Quantum Dot I = 10 5 × | E 0 | 2

4 Model -i ω t (Drive) F (t)= Fe a) b) Nanoantenna Gold + | e > ρ eg q ћω eg - | g > Quantum Dot Quantum Classical Oscillator Oscillator life-time of coupled [2] a simple model plasmon extends [2] M. Emre Taşgın, Nanoscale 5 , 8616 (2013).

5 Spaser ( Surface Plasmon Amplification by stimulated emission of radiation ) [3] MNP moleküller ile etkilişiyor [2] M. Emre Taşgın, Nanoscale 5 , 8616 (2013). [3] Noginov et al. , Nature 460 ,1110 (2009).

5 Spaser ( Surface Plasmon Amplification by stimulated emission of radiation ) [3] life-time of MNP [3] narrowing in the plasmon moleküller ile [2] emission band of MNP explains etkilişiyor extends [2] M. Emre Taşgın, Nanoscale 5 , 8616 (2013). [3] Noginov et al. , Nature 460 ,1110 (2009).

6 Enhancing/Suppressing Nonlinear Response ω QD at the hot-spot ? ? 2 ω MNP cross-section [4] D. Turkpence, Gursoy B. Akguc, Alpan Bek, M. E. Tasgin, J. Opt. 16 , 105009 (2014).

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

8 Result Result: γ 2 γ 1 decay rate of ω 1 -mode decay rate of |𝛽 1 | 2 = ω plasmon |𝛽 2 | 2 = 2ω plasmon ω 2 -mode occupasion occupasion f 2 = MNP – QD coupling ω eg χ (2) = nonlinear susceptibility [4] D. Turkpence, Gursoy B. Akguc, Alpan Bek, M. E. Tasgin, J. Opt. 16 , 105009 (2014).

9 SHG Enhancement Result: choose ω eg such that 0 𝑗(𝜕 2 − 2𝜕) imag part f 2 = MNP – QD coupling

9 SHG Enhancement SHG enhancement factor Result: choose ω eg such that 0 𝑗(𝜕 2 − 2𝜕) imag part f 2 = MNP – QD coupling

9 SHG Enhancement SHG enhancement factor Referees asked What about retardation effects?

10 3D Boundary Element Method Simulations (exact solutions) SHG cross-section (nm 2 ) SHG cross-section (nm 2 ) (a) (b) MNPBEM MNPBEM Simulation Simulation single coupled λ sh = λ exc /2 (nm) λ sh = λ exc /2 (nm) QD Fano resonance induces SHG from 100 times single MNP ( 4 nm 2 ) SHG enhancement ( 500 nm 2 )

11 So what? SHG enhancement due to Fano resonances already shown already shown via experimentally 3D simulations so what is the point here? no one explained as OK, but what this explanation worth ?

12 1 MNP and 2 QDs 10 7 times SHG enhancement!! [8] M. E. Tasgin, “ Divergent nonlinear optical response of three resonator system via Fano resonances ” arXiv:1404.3901

14 SHG suppression Result: very large ! choose 𝜕 𝑓𝑕 ≈ 2𝜕 1/ γ 𝑓𝑕 γ 𝑓𝑕 ≈ 10 −5 𝜕 |α 2 | very large very small ! good to prevent SHG loses SHG in fiber lasers suppressed 21 View publication stats View publication stats