All-dielectric grating quasi-BIC for upconversion luminescence enhancement and cryogenic temperature sensing
Year: 2026
Type: article
Abstract: Upconversion nanoparticles (UCNPs) are limited in their applications in non-contact temperature measurement and biomedicine due to their low luminescence quantum efficiency. Traditional surface plasmon resonance (SPR) structures are restricted in their performance and practical application due to the small local field enhancement amplitude and the low quality factor (Q factor) caused by the intrinsic loss of metals. However, bound states in the continuum (BIC) can achieve an extremely high Q factor and a huge local field enhancement by precisely harnessing the size and resonance wavelength of all-dielectric metasurfaces, while avoiding the quenching effect. Therefore, we propose an effective strategy for enhancing upconversion luminescence based on quasi-BIC in all-dielectric gratings. This design uses all-dielectric gratings to support a high-Q resonant mode at 980 nm, and simultaneously provides a local field enhancement far greater than existing SPR structures. Through finite element simulation calculations, the enhancement factor reaches 1.58 × 10 15 . Moreover, by coating the grating-UCNPs structure surface with an ethanol film whose refractive index changes linearly with temperature, the temperature variation can be directly characterized by the luminescence intensity, achieving optical-temperature sensing with a maximum sensitivity of 0.429 K −1 and a low-temperature (163 K) sensitivity of 0.022 K −1 . This research result can provide a new strategy for the design and application of new low-power ultra-low-temperature nanoscale temperature sensors.
Source: Optics & Laser Technology
Language: English
Field: Materials Science
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $3,230
OpenAlex ID: W7214537614