Limits...
Hybridization in Three Dimensions: A Novel Route toward Plasmonic Metamolecules.

Zilio P, Malerba M, Toma A, Zaccaria RP, Jacassi A, De Angelis F - Nano Lett. (2015)

Bottom Line: This configuration mimics an out-of-plane split ring resonator capable of a strong near-field interaction at the terminations and a strong diffractive coupling with nearby nanostructures.Compared to the corresponding planar counterparts, higher values of electric and magnetic fields are found (about a factor 10 and a factor 3, respectively).High-quality-factor resonances (Q ≈ 390) are produced in the mid-IR as a result of the efficient excitation of collective modes in dimer arrays.

View Article: PubMed Central - PubMed

Affiliation: †Istituto Italiano di Tecnologia, Via Morego 30, 16163 Genova, Italy.

ABSTRACT
Plasmonic metamolecules have received much interest in the last years because they can produce a wide spectrum of different hybrid optical resonances. Most of the configurations presented so far, however, considered planar resonators lying on a dielectric substrate. This typically yields high damping and radiative losses, which severely limit the performance of the system. Here we show that these limits can be overcome by considering a 3D arrangement made from slanted nanorod dimers extruding from a silver baseplate. This configuration mimics an out-of-plane split ring resonator capable of a strong near-field interaction at the terminations and a strong diffractive coupling with nearby nanostructures. Compared to the corresponding planar counterparts, higher values of electric and magnetic fields are found (about a factor 10 and a factor 3, respectively). High-quality-factor resonances (Q ≈ 390) are produced in the mid-IR as a result of the efficient excitation of collective modes in dimer arrays.

No MeSH data available.


(a) Simulated total reflectance of a slanted nanorod dimerarray with illumination condition as in the inset of Figure 1c, as a function of pitch andwavelength. Geometrical parameters are the same reported in Figure 1. The bonding andantibonding resonant wavelengths of the isolated structures are markedwith horizontal black dashed lines, while Wood–Rayleigh anomaliesare marked with white dashed lines. The insets report the Ez field maps in two sampleconfigurations. (b) SEM micrograph of a fabricated sample. (c) Crosssection of the map in (a) corresponding to the green dashed line.(d,e) Simulated 0th order reflectance (averaged between TE and TMpolarizations) of an array with gap g = 100 nm forthree sample pitches, (d), and of an array with p = 4 μm for some values of gap g, (e). (f),(g) Corresponding experimental reflectances.
© Copyright Policy
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4593574&req=5

fig4: (a) Simulated total reflectance of a slanted nanorod dimerarray with illumination condition as in the inset of Figure 1c, as a function of pitch andwavelength. Geometrical parameters are the same reported in Figure 1. The bonding andantibonding resonant wavelengths of the isolated structures are markedwith horizontal black dashed lines, while Wood–Rayleigh anomaliesare marked with white dashed lines. The insets report the Ez field maps in two sampleconfigurations. (b) SEM micrograph of a fabricated sample. (c) Crosssection of the map in (a) corresponding to the green dashed line.(d,e) Simulated 0th order reflectance (averaged between TE and TMpolarizations) of an array with gap g = 100 nm forthree sample pitches, (d), and of an array with p = 4 μm for some values of gap g, (e). (f),(g) Corresponding experimental reflectances.

Mentions: We study in detail this aspect by scatteringsimulations of squared dimer arrays considering the same dimer geometricalparameters as in the Figure 1 caption with TM polarized illumination and scattering planeas in Figure 1c. Thecalculated total reflectance as a function of impinging wavelengthand array pitch is reported in Figure 4a.


Hybridization in Three Dimensions: A Novel Route toward Plasmonic Metamolecules.

Zilio P, Malerba M, Toma A, Zaccaria RP, Jacassi A, De Angelis F - Nano Lett. (2015)

(a) Simulated total reflectance of a slanted nanorod dimerarray with illumination condition as in the inset of Figure 1c, as a function of pitch andwavelength. Geometrical parameters are the same reported in Figure 1. The bonding andantibonding resonant wavelengths of the isolated structures are markedwith horizontal black dashed lines, while Wood–Rayleigh anomaliesare marked with white dashed lines. The insets report the Ez field maps in two sampleconfigurations. (b) SEM micrograph of a fabricated sample. (c) Crosssection of the map in (a) corresponding to the green dashed line.(d,e) Simulated 0th order reflectance (averaged between TE and TMpolarizations) of an array with gap g = 100 nm forthree sample pitches, (d), and of an array with p = 4 μm for some values of gap g, (e). (f),(g) Corresponding experimental reflectances.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4593574&req=5

fig4: (a) Simulated total reflectance of a slanted nanorod dimerarray with illumination condition as in the inset of Figure 1c, as a function of pitch andwavelength. Geometrical parameters are the same reported in Figure 1. The bonding andantibonding resonant wavelengths of the isolated structures are markedwith horizontal black dashed lines, while Wood–Rayleigh anomaliesare marked with white dashed lines. The insets report the Ez field maps in two sampleconfigurations. (b) SEM micrograph of a fabricated sample. (c) Crosssection of the map in (a) corresponding to the green dashed line.(d,e) Simulated 0th order reflectance (averaged between TE and TMpolarizations) of an array with gap g = 100 nm forthree sample pitches, (d), and of an array with p = 4 μm for some values of gap g, (e). (f),(g) Corresponding experimental reflectances.
Mentions: We study in detail this aspect by scatteringsimulations of squared dimer arrays considering the same dimer geometricalparameters as in the Figure 1 caption with TM polarized illumination and scattering planeas in Figure 1c. Thecalculated total reflectance as a function of impinging wavelengthand array pitch is reported in Figure 4a.

Bottom Line: This configuration mimics an out-of-plane split ring resonator capable of a strong near-field interaction at the terminations and a strong diffractive coupling with nearby nanostructures.Compared to the corresponding planar counterparts, higher values of electric and magnetic fields are found (about a factor 10 and a factor 3, respectively).High-quality-factor resonances (Q ≈ 390) are produced in the mid-IR as a result of the efficient excitation of collective modes in dimer arrays.

View Article: PubMed Central - PubMed

Affiliation: †Istituto Italiano di Tecnologia, Via Morego 30, 16163 Genova, Italy.

ABSTRACT
Plasmonic metamolecules have received much interest in the last years because they can produce a wide spectrum of different hybrid optical resonances. Most of the configurations presented so far, however, considered planar resonators lying on a dielectric substrate. This typically yields high damping and radiative losses, which severely limit the performance of the system. Here we show that these limits can be overcome by considering a 3D arrangement made from slanted nanorod dimers extruding from a silver baseplate. This configuration mimics an out-of-plane split ring resonator capable of a strong near-field interaction at the terminations and a strong diffractive coupling with nearby nanostructures. Compared to the corresponding planar counterparts, higher values of electric and magnetic fields are found (about a factor 10 and a factor 3, respectively). High-quality-factor resonances (Q ≈ 390) are produced in the mid-IR as a result of the efficient excitation of collective modes in dimer arrays.

No MeSH data available.