Metallo-dielectric hybrid antenna for high Purcell factor and radiation efficiency

Zeng, Xianghao; Yu, Wenhai; Yao, Peiju; Xi, Zheng; Lü, Yonghua; Wang, Pei

doi:10.1364/oe.22.014517

Cited by 22 publications

(19 citation statements)

References 23 publications

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“…57,[62][63][64] The values of the elements of the Raman tensor R ν and the zero-point amplitude Q 0 ν vary significantly for different molecules and each vibrational degree of freedom. The estimates of these values have been provided from theoretical and experimental studies for numerous molecules, including rhodamine 6g (R6G) 65 or various peptides, 66 as well as cluster structures of e.g., silicon.…”

Section: Cavity-vibrations Couplingmentioning

confidence: 99%

Quantum Mechanical Description of Raman Scattering from Molecules in Plasmonic Cavities

et al. 2016

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Plasmon-enhanced Raman scattering can push single-molecule vibrational spectroscopy beyond a regime addressable by classical electrodynamics. We employ a quantum electrodynamics (QED) description of the coherent interaction of plasmons and molecular vibrations that reveal the emergence of nonlinearities in the inelastic response of the system. For realistic situations, we predict the onset of phonon-stimulated Raman scattering and a counterintuitive dependence of the anti-Stokes emission on the frequency of excitation. We further show that this QED framework opens a venue to analyze the correlations of photons emitted from a plasmonic cavity.Surface Enhanced Raman Scattering (SERS) is a spectroscopic technique in which the inelastic scattering from a molecule is increased by placing it in a hotspot of a plasmonic cavity, where the electric fields associated with the incident and the scattered photons are strongly enhanced (see the schematic in Fig. 1(a)). 1 The difference between the energy of those two photons provides a fingerprint of the molecule, i.e., detailed chemical information about its vibrational structure. Since the initial observation of Raman scattering from single molecules, 2,3 the use of a variety of plasmonic structures that act as effective optical nanoantennas over the last decades has allowed a tremendous advance of this molecular spectroscopy 4 . Metallic particles such as nanoshells 5,6 , nanorings 7 , nanorods 8 , nanowires 9 , or nano stars 10 , as well as plasmonic nanogap structures formed in particle dimers [11][12][13] , nanoparticle-on-a-mirror morphologies [14][15][16][17] , or nanoclusters 18 , are among the variety of structures that offer huge and controllable enhancements of the field intensity in their hotspots, boosting the inherently weak Raman scattering intensity, 1,19 and ultimately enabling the chemical identification and imaging of particular vibrational modes of a molecule with subnanometer resolution. 20 These results suggest that some experiments might have reached the regime where the quantum-mechanical nature of both the molecular vibrations and the plasmonic cavity emerges, 21 and call for an adequate theoretical description that goes beyond the classical treatment of the electric fields produced in plasmonic cavities. 1,22,23 In this work we address the underlying quantummechanical nature of Raman scattering processes by quantizing as bosonic excitations both the vibrations of the molecule and the electromagnetic field of a plasmonic cavity. The description of the vibrations through bosonic operators can be justified by considering the harmonic approximation to the energy landscape of the molecule along a generalized atomic coordinate ( Fig. 1(b)), such as the length of a molecular bond, e.g., C=O. 21,22 These vibrations interact with the cavity photons through a nonlinear Hamiltonian, reminiscent of that found in optomechanical systems. 24 In this description, the large enhancement of the Raman scattering from a molecule in the plasmonic cavity occurs thanks to ...

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Section: Cavity-vibrations Couplingmentioning

confidence: 99%

Quantum Mechanical Description of Raman Scattering from Molecules in Plasmonic Cavities

et al. 2016

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“…As a result, it makes silicon nanoparticles the best candidates for lossless magnetic response at high frequencies. One of their most successful applications is the superior performance of hybrid and all-dielectric nanoantennas for effective control of light emission from localized sources [13][14][15][16][17][18][19]. Strong near-field enhancement in resonant dielectric nanostructures [20,21] implies that strong nonlinear phenomena can be expected in the nonlinear optical response of dielectric nanoparticles with high refractive index.…”

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confidence: 99%

“…Combining both metallic and dielectric meta-atoms allows to create hybrid metamaterials taking the advantages of both plasmonic and all-dielectric elements. In particular, such structures may offer large Purcell enhancements and highly directional radiation patterns while preserving high radiation efficiencies [16,17]. However, the current study of combined effects of metallic and dielectric hybrid nanostructures on the magnetic nanostructures is very limited, and it is mainly restricted by the radiation control [12].…”

mentioning

confidence: 99%

Antiferromagnetic order in hybrid electromagnetic metamaterials

et al. 2017

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We demonstrate experimentally a new type of order in optical magnetism resembling the staggered structure of spins in antiferromagnetic ordered materials. We study hybrid electromagnetic metasurfaces created by assembling hybrid meta-atoms formed by metallic split-ring resonators and dielectric particles with a high refractive index, both supporting optically-induced magnetic dipole resonances of different origin. Each pair (or 'metamolecule') is characterized by two interacting magnetic dipole moments with the distance-dependent magnetization resembling the spin exchange interaction in magnetic materials. By directly mapping the structure of the electromagnetic fields, we demonstrate experimentally that strong coupling between the optically-induced magnetic moments of different origin can flip the magnetisation orientation in a metamolecule creating an antiferromagnetic lattice of staggered optically-induced magnetic moments in hybrid metasurfaces.

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“…The transition rate is directly proportional to the PMD as stated in the Fermi's golden rule:

{normalΓ}_{i j} \propto | M_{i j} {false|}^{2} ρ (υ_{i j})

, where Γ ij is the transition rate, M ij is the matrix element, and

ρ (υ_{i j})

is the PMD. The ratio of the transition rate in the presence of metal to the transition rate in the absence of metal is a key parameter known as Purcell factor ( F p ), which plays an important role in the enhancement of spontaneous emission. Purcell factor can be obtained in the simulation by placing the dipole near the metallic ND surface and calculating the ratio of the dipole power with metallic ND ( P 1 ) to the source power, which is the dipole power in the homogenous environment ( P 0 ).…”

Section: Resultsmentioning

confidence: 99%

How Effective is Plasmonic Enhancement of Colloidal Quantum Dots for Color‐Conversion Light‐Emitting Devices?

Park¹,

Isnaeni

Gong

et al. 2017

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Enhancing the fluorescence intensity of colloidal quantum dots (QDs) in case of color-conversion type QD light-emitting devices (LEDs) is very significant due to the large loss of QDs and their quantum yields during fabrication processes, such as patterning and spin-coating, and can therefore improve cost-effectiveness. Understanding the enhancement process is crucial for the design of metallic nanostructure substrates for enhancing the fluorescence of colloidal QDs. In this work, improved color conversion of colloidal green and red QDs coupled with aluminum (Al) and silver (Ag) nanodisk (ND) arrays designed by in-depth systematic finite-difference time domain simulations of excitation, spontaneous emission, and quantum efficiency enhancement is reported. Calculated results of the overall photoluminescence enhancement factor in the substrate of 500 × 500 µm size are 2.37-fold and 2.82-fold for Al ND-green QD and Ag ND-red QD structures, respectively. Experimental results are in good agreement, showing 2.26-fold and 2.66-fold enhancements for Al ND and Ag ND structures. Possible uses of plasmonics in cases such as white LED and total color conversion for possible display applications are discussed. The theoretical treatments and experiments shown in this work are a proof of principle for future studies of plasmonic enhancement of various light-emitting materials.

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Metallo-dielectric hybrid antenna for high Purcell factor and radiation efficiency

Cited by 22 publications

References 23 publications

Quantum Mechanical Description of Raman Scattering from Molecules in Plasmonic Cavities

Quantum Mechanical Description of Raman Scattering from Molecules in Plasmonic Cavities

Antiferromagnetic order in hybrid electromagnetic metamaterials

How Effective is Plasmonic Enhancement of Colloidal Quantum Dots for Color‐Conversion Light‐Emitting Devices?

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