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Giant electric field enhancement in split ring resonators featuring nanometer-sized gaps.

Bagiante S, Enderli F, Fabiańska J, Sigg H, Feurer T - Sci Rep (2015)

Bottom Line: Today's pulsed THz sources enable us to excite, probe, and coherently control the vibrational or rotational dynamics of organic and inorganic materials on ultrafast time scales.Here, we demonstrate resonant electric field enhancement structures, which concentrate the incident electric field in sub-diffraction size volumes and show an electric field enhancement as high as ~14,000 at 50 GHz.These values have been confirmed through a combination of near-field imaging experiments and electromagnetic simulations.

View Article: PubMed Central - PubMed

Affiliation: 1] Laboratory of Micro- and Nanotechnology Paul Scherrer Institute, Villigen 5232, Switzerland [2] Institute of Applied Physics University of Bern, Bern 3012, Sidlerstrasse 5, Switzerland.

ABSTRACT
Today's pulsed THz sources enable us to excite, probe, and coherently control the vibrational or rotational dynamics of organic and inorganic materials on ultrafast time scales. Driven by standard laser sources THz electric field strengths of up to several MVm(-1) have been reported and in order to reach even higher electric field strengths the use of dedicated electric field enhancement structures has been proposed. Here, we demonstrate resonant electric field enhancement structures, which concentrate the incident electric field in sub-diffraction size volumes and show an electric field enhancement as high as ~14,000 at 50 GHz. These values have been confirmed through a combination of near-field imaging experiments and electromagnetic simulations.

No MeSH data available.


(a) Absolute value of the electric field enhancement in the gap as a function of frequency for the three gap widths 100 nm, 500 nm, and 970 nm, respectively. Absolute electric field amplitude of the incident THz spectrum in gray. (b) Electric field enhancement distribution in a 500 nm gap SRR at 56 GHz. (c) In-gap electric field strength versus time for the 100 nm wide gap.
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f4: (a) Absolute value of the electric field enhancement in the gap as a function of frequency for the three gap widths 100 nm, 500 nm, and 970 nm, respectively. Absolute electric field amplitude of the incident THz spectrum in gray. (b) Electric field enhancement distribution in a 500 nm gap SRR at 56 GHz. (c) In-gap electric field strength versus time for the 100 nm wide gap.

Mentions: Figure 4a) shows the simulated in-gap electric field enhancement as a function of frequency for all three gap widths examined. The black vertical dashed line marks the calibration points for all three gap widths at the third order resonance frequencies ν3. For a 100 nm wide gap the maximum electric field enhancement is as high as 14300 at the fundamental resonance and 3400 at the third order resonance. As mentioned above the electric field enhancement at the individual resonances differ because of the different character of the charge distribution on the split ring structure. At the lowest order resonance the charge is known to accumulate predominantly around the gap. Conversely, at the third order resonance, the charges accumulate at the two corners opposite to the gap36, therefore the electric field enhancement is lower. The spatial in-gap distribution of the electric field enhancement in the xy plane (at z = h/2 = 30 nm, g = 500 nm, v1 = 56 GHz) is shown in Figure 4b). Except some variations at the edges, it is relatively homogeneous in the entire region.


Giant electric field enhancement in split ring resonators featuring nanometer-sized gaps.

Bagiante S, Enderli F, Fabiańska J, Sigg H, Feurer T - Sci Rep (2015)

(a) Absolute value of the electric field enhancement in the gap as a function of frequency for the three gap widths 100 nm, 500 nm, and 970 nm, respectively. Absolute electric field amplitude of the incident THz spectrum in gray. (b) Electric field enhancement distribution in a 500 nm gap SRR at 56 GHz. (c) In-gap electric field strength versus time for the 100 nm wide gap.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4306966&req=5

f4: (a) Absolute value of the electric field enhancement in the gap as a function of frequency for the three gap widths 100 nm, 500 nm, and 970 nm, respectively. Absolute electric field amplitude of the incident THz spectrum in gray. (b) Electric field enhancement distribution in a 500 nm gap SRR at 56 GHz. (c) In-gap electric field strength versus time for the 100 nm wide gap.
Mentions: Figure 4a) shows the simulated in-gap electric field enhancement as a function of frequency for all three gap widths examined. The black vertical dashed line marks the calibration points for all three gap widths at the third order resonance frequencies ν3. For a 100 nm wide gap the maximum electric field enhancement is as high as 14300 at the fundamental resonance and 3400 at the third order resonance. As mentioned above the electric field enhancement at the individual resonances differ because of the different character of the charge distribution on the split ring structure. At the lowest order resonance the charge is known to accumulate predominantly around the gap. Conversely, at the third order resonance, the charges accumulate at the two corners opposite to the gap36, therefore the electric field enhancement is lower. The spatial in-gap distribution of the electric field enhancement in the xy plane (at z = h/2 = 30 nm, g = 500 nm, v1 = 56 GHz) is shown in Figure 4b). Except some variations at the edges, it is relatively homogeneous in the entire region.

Bottom Line: Today's pulsed THz sources enable us to excite, probe, and coherently control the vibrational or rotational dynamics of organic and inorganic materials on ultrafast time scales.Here, we demonstrate resonant electric field enhancement structures, which concentrate the incident electric field in sub-diffraction size volumes and show an electric field enhancement as high as ~14,000 at 50 GHz.These values have been confirmed through a combination of near-field imaging experiments and electromagnetic simulations.

View Article: PubMed Central - PubMed

Affiliation: 1] Laboratory of Micro- and Nanotechnology Paul Scherrer Institute, Villigen 5232, Switzerland [2] Institute of Applied Physics University of Bern, Bern 3012, Sidlerstrasse 5, Switzerland.

ABSTRACT
Today's pulsed THz sources enable us to excite, probe, and coherently control the vibrational or rotational dynamics of organic and inorganic materials on ultrafast time scales. Driven by standard laser sources THz electric field strengths of up to several MVm(-1) have been reported and in order to reach even higher electric field strengths the use of dedicated electric field enhancement structures has been proposed. Here, we demonstrate resonant electric field enhancement structures, which concentrate the incident electric field in sub-diffraction size volumes and show an electric field enhancement as high as ~14,000 at 50 GHz. These values have been confirmed through a combination of near-field imaging experiments and electromagnetic simulations.

No MeSH data available.