Numerical Study on a Bound State in the Continuum Assisted Plasmonic Refractive Index Sensor

Plasmonic sensors have attracted intensive attention due to their high sensitivity. However, due to intrinsic metallic loss, plasmonic sensors usually have a large full width at half maximum (FWHM) that limits the wavelength resolution. In this paper, we numerically investigate and propose a dielect...

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Bibliographic Details
Published inPhotonics Vol. 9; no. 4; p. 224
Main Authors Tang, Shulin, Chang, Chang, Zhou, Peiji, Zou, Yi
Format Journal Article
LanguageEnglish
Published Basel MDPI AG 01.04.2022
Subjects
bound states in the continuum
Figure of merit
Glass substrates
Light
Magnetic fields
plasmonic
Plasmonics
Radiation
Refractivity
Sensitivity
sensor
Sensors
Silica
Silver
Symmetry
Wavelengths
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Summary:Plasmonic sensors have attracted intensive attention due to their high sensitivity. However, due to intrinsic metallic loss, plasmonic sensors usually have a large full width at half maximum (FWHM) that limits the wavelength resolution. In this paper, we numerically investigate and propose a dielectric grating-assisted plasmonic device, leveraging the bound states in the continuum (BIC) effect to suppress the FWHM of the resonance. We initiate quasi-SP-BIC modes at 1559 nm and 1905 nm wavelengths by slightly tilting the incident angle at 2° to break the symmetry, featuring a narrow linewidth of 1.8 nm and 0.18 nm at these two wavelengths, respectively. Refractive index sensing has also been investigated, showing high sensitivity of 938 nm/RIU and figure of merit (FOM) of 521/RIU at 1559 nm and even higher sensitivity of 1264 nm/RIU and FOM of 7022/RIU at 1905 nm.
ISSN:2304-6732
2304-6732
DOI:10.3390/photonics9040224