High-performance refractive index sensor by nano-cylindrical surface structure

In this work, a two-dimensional grating structure based on the metal assisted guided-mode resonance (MAGMR) effect is proposed, which can be used for near infrared band sensing in an aqueous environment. Following optimization by the finite-difference time-domain method, the structure is able to support MAGMR well, and has an excellent reflection dip. The electromagnetic field shows that the structure not only interacts well with the sensing medium but also has a large penetration depth. Results at different refractive indices of the sensing medium confirm the high sensing performance of the proposed MAGMR sensor, which achieves a sensitivity of 852 nm/RIU. Meanwhile, the sensor has a figure of merit up to 4813 RIU-1 (55 times typical GMR sensors) because of the full width at half maximum is only 0.177 nm. Furthermore, the shape and parameters of the MAGMR sensor have been analyzed in detail in order to gain a comprehensive understanding of its performance. This MAGMR sensor is promising for future applications in biomedicine, chemical measurements and environmental monitoring due to its polarization-independent, non-specific angle of incidence, high penetration depth and high sensing performance.

Automated summary

In this work, a two-dimensional grating structure based on the metal assisted guided-mode resonance (MAGMR) effect is proposed for near infrared band sensing in an aqueous environment. The structure is optimized by the finite-difference time-domain method to support MAGMR and achieve excellent reflection dip. The electromagnetic field analysis shows that the structure has good interaction with the sensing medium and a large penetration depth. Experimental results confirm the high sensing performance of the MAGMR sensor at different refractive indices, achieving a sensitivity of 852 nm/RIU. The sensor also has a high figure of merit due to its small full width at half maximum. The shape and parameters of the MAGMR sensor have been analyzed in detail for a comprehensive understanding of its performance. With its polarization-independent, non-specific angle of incidence, high penetration depth, and high sensing performance, this MAGMR sensor shows promising applications in biomedicine, chemical measurements, and environmental monitoring.