Multi-function sensing applications based on high Q-factor multi-Fano resonances in an all-dielectric metastructure

Area of Science:

• Photonics and Metamaterials
• Nanotechnology
• Sensing Technologies

Background:

• Metamaterials offer unique optical properties for sensing applications.
• Simultaneous multi-parameter sensing remains a challenge in various scientific fields.
• Fano resonances in dielectric structures enable high-sensitivity detection.

Purpose of the Study:

• To design and analyze a multi-function sensor based on an all-dielectric metastructure.
• To achieve simultaneous temperature and refractive index sensing.
• To investigate the sensing performance and resonant modes of the proposed structure.

Main Methods:

• Design of a periodic array of silicon dimers on a silicon dioxide substrate.
• Excitation of quasi-bound states in the continuum (qBIC) and Fano resonances.
• Analysis of electromagnetic field distributions to identify resonant modes (magnetic dipole, magnetic toroidal dipole, electric toroidal dipole).
• Investigation of temperature and refractive index sensing characteristics.

Main Results:

• Three Fano resonances were excited in the near-infrared region.
• The sensor achieved a maximum Q-factor of 9352 and a modulation depth near 100%.
• Maximum temperature sensitivity was 60 pm/K.
• Refractive index sensing yielded a sensitivity of 279.5 nm/RIU and a figure of merit of 2055.1 RIU^-1.

Conclusions:

• The all-dielectric metastructure demonstrates significant potential for simultaneous multi-parameter sensing.
• The sensor's high performance metrics suggest suitability for advanced biological and chemical sensing applications.
• The study highlights the versatility of dielectric metamaterials for complex sensing tasks.