Abstract
Metasurface studies have demonstrated vast applications to control optical properties of light based on the ability to design unit cells with desired phase and reflectivity in 2D subwavelength periodic arrays. The simplified design strategy is only an approximation since the unit cells can be subject to near-field coupling effects due to influence from neighbor unit cells. In this work, we try to investigate this effect by numerically and experimentally studying the near-field response from gold nanobricks of varied length, fabricated in both quasi-periodic and periodic configuration on top of dielectric-coated (SiO2) layer and gold layer at telecommunication wavelength (1500 nm), which is the commonly used gap plasmon configuration for efficient metasurfaces. The experimental near-field investigation is performed using a phase-resolved scattering-type scanning near-field optical microscopy (s-SNOM) in the transmission mode. We demonstrate that near-field coupling becomes significant when edge-to-edge separation between GSP elements goes below ∼200-250 nm. We also show that the reflection phase of any GSP element is approximately equal to its doubled near-field phase. Thus, our studies provide a direct explanation of a reduced performance of a densely-packed GSP metasurfaces. This technique can accurately predict the performance of different types of metasurfaces by observing their near-field response in different periodic configurations by considering factors ignored in the design stage, which include fabrication uncertainties, wrong design considerations along with near-field coupling effects.
| Original language | English |
|---|---|
| Title of host publication | Proceedings of SPIE Photonics Europe : Metamaterials XI |
| Editors | Anatoly V. Zayats, Allan D. Boardman, Kevin F. MacDonald |
| Volume | 10671 |
| Publisher | SPIE - International Society for Optical Engineering |
| Publication date | May 2018 |
| Article number | 1067129 |
| ISBN (Electronic) | 9781510618688 |
| DOIs | |
| Publication status | Published - May 2018 |
| Event | Spie Photonics Europe - Strasbourg, France Duration: 22. Apr 2018 → 26. Apr 2018 |
Conference
| Conference | Spie Photonics Europe |
|---|---|
| Country | France |
| City | Strasbourg |
| Period | 22/04/2018 → 26/04/2018 |
| Sponsor | CNRS - The National Center for Scientific Research, et al., iCube, Investissements d'Avenvir, Strasbourg the Europtimist, The Society of Photo-Optical Instrumentation Engineers (SPIE) |
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Keywords
- gap surface plasmons
- metasurfaces
- Near-field
- s-SNOM
Cite this
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Near-field phase characterization of gradient gap plasmon-based metasurfaces. / Deshpande, Rucha A.; Zenin, Vladimir A.; Ding, Fei; Mortensen, Niels A.; Bozhevolnyi, Sergey I.
Proceedings of SPIE Photonics Europe: Metamaterials XI. ed. / Anatoly V. Zayats; Allan D. Boardman; Kevin F. MacDonald. Vol. 10671 SPIE - International Society for Optical Engineering, 2018. 1067129.Research output: Chapter in Book/Report/Conference proceeding › Article in proceedings › Research › peer-review
TY - GEN
T1 - Near-field phase characterization of gradient gap plasmon-based metasurfaces
AU - Deshpande, Rucha A.
AU - Zenin, Vladimir A.
AU - Ding, Fei
AU - Mortensen, Niels A.
AU - Bozhevolnyi, Sergey I.
PY - 2018/5
Y1 - 2018/5
N2 - Metasurface studies have demonstrated vast applications to control optical properties of light based on the ability to design unit cells with desired phase and reflectivity in 2D subwavelength periodic arrays. The simplified design strategy is only an approximation since the unit cells can be subject to near-field coupling effects due to influence from neighbor unit cells. In this work, we try to investigate this effect by numerically and experimentally studying the near-field response from gold nanobricks of varied length, fabricated in both quasi-periodic and periodic configuration on top of dielectric-coated (SiO2) layer and gold layer at telecommunication wavelength (1500 nm), which is the commonly used gap plasmon configuration for efficient metasurfaces. The experimental near-field investigation is performed using a phase-resolved scattering-type scanning near-field optical microscopy (s-SNOM) in the transmission mode. We demonstrate that near-field coupling becomes significant when edge-to-edge separation between GSP elements goes below ∼200-250 nm. We also show that the reflection phase of any GSP element is approximately equal to its doubled near-field phase. Thus, our studies provide a direct explanation of a reduced performance of a densely-packed GSP metasurfaces. This technique can accurately predict the performance of different types of metasurfaces by observing their near-field response in different periodic configurations by considering factors ignored in the design stage, which include fabrication uncertainties, wrong design considerations along with near-field coupling effects.
AB - Metasurface studies have demonstrated vast applications to control optical properties of light based on the ability to design unit cells with desired phase and reflectivity in 2D subwavelength periodic arrays. The simplified design strategy is only an approximation since the unit cells can be subject to near-field coupling effects due to influence from neighbor unit cells. In this work, we try to investigate this effect by numerically and experimentally studying the near-field response from gold nanobricks of varied length, fabricated in both quasi-periodic and periodic configuration on top of dielectric-coated (SiO2) layer and gold layer at telecommunication wavelength (1500 nm), which is the commonly used gap plasmon configuration for efficient metasurfaces. The experimental near-field investigation is performed using a phase-resolved scattering-type scanning near-field optical microscopy (s-SNOM) in the transmission mode. We demonstrate that near-field coupling becomes significant when edge-to-edge separation between GSP elements goes below ∼200-250 nm. We also show that the reflection phase of any GSP element is approximately equal to its doubled near-field phase. Thus, our studies provide a direct explanation of a reduced performance of a densely-packed GSP metasurfaces. This technique can accurately predict the performance of different types of metasurfaces by observing their near-field response in different periodic configurations by considering factors ignored in the design stage, which include fabrication uncertainties, wrong design considerations along with near-field coupling effects.
KW - gap surface plasmons
KW - metasurfaces
KW - Near-field
KW - s-SNOM
U2 - 10.1117/12.2306223
DO - 10.1117/12.2306223
M3 - Article in proceedings
VL - 10671
BT - Proceedings of SPIE Photonics Europe
A2 - Zayats, Anatoly V.
A2 - Boardman, Allan D.
A2 - MacDonald, Kevin F.
PB - SPIE - International Society for Optical Engineering
ER -