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Demonstration of Equal-Intensity Beam Generation by Dielectric Metasurfaces
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Anapole Modes in Hollow Nanocuboid Dielectric Metasurfaces for Refractometric Sensing
José Francisco Algorri1, Dimitrios C Zografopoulos2, Antonio Ferraro3
1GDAF-UC3M, Displays and Photonics Applications Group, Department of Electronic Technology, Carlos III University of Madrid, Leganés, 28911 Madrid, Spain. jalgorri@ing.uc3m.es.
Nanomaterials (Basel, Switzerland)
|December 29, 2018
Summary
This study introduces a new sensing method using silicon nanocuboid metasurfaces. These structures exhibit ultrahigh-Q anapole modes for highly sensitive refractive index detection, enabling advanced optical applications.
Area of Science:
- Nanophotonics and Metasurfaces
- Optical Sensing Technologies
- Silicon Nanotechnology
Background:
- Non-radiating anapole modes in high-refractive-index nanoparticles offer unique optical properties.
- Metasurfaces composed of periodic nanoparticle arrays enable tailored light-matter interactions.
- Refractive index sensing is crucial for various scientific and industrial applications.
Purpose of the Study:
- To propose and investigate a novel sensing principle based on anapole modes in silicon nanocuboid metasurfaces.
- To explore the dependence of anapole mode spectral position on nanocuboid geometry.
- To design metasurfaces for ultrahigh Q-factor resonances at infrared wavelengths for refractometric sensing.
Main Methods:
- Investigated spectral positions of anapole modes in hollow silicon nanocuboids as a function of geometry.
- Designed periodic arrays of nanocuboids on a glass substrate to form nanostructured metasurfaces.
- Optimized metasurface parameters to achieve ultrahigh Q-factor (>1 million) resonance at 1.55 µm.
Main Results:
- Anapole modes in hollow silicon nanocuboids were characterized and their spectral positions analyzed.
- Metasurfaces with periodic arrays of nanocuboids exhibited resonances with Q-factors exceeding one million.
- The anapole-induced resonant wavelength showed high sensitivity (up to 180 nm/RIU) to the surrounding refractive index.
Conclusions:
- The proposed silicon nanocuboid metasurfaces enable highly sensitive refractometric sensing with very low detection limits.
- The ultrahigh Q-factor and high sensitivity make the device suitable for a broad range of refractive indices.
- The technology holds potential for applications in non-linear optics, optical switches, and optical communications.
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