Design and optimization of Bloch surface wave sensor with high sensitivity and quality factor using LiNbO3

Abstract

This work presents a refractive index sensor based on Bloch surface waves (BSW) with high sensitivity and quality factor (Q). The sensor utilizes a one-dimensional photonic crystal TiO 2 ∕MgF 2 as a distributed Bragg reflector and employs a LiNbO 3 thin film as the top defect layer to excite BSW through a Kretschmann prism. Numerical simulations using the rigorous coupled wave analysis method are conducted to explore various prism configurations, revealing that low refractive index prisms yield superior performance for BSW sensors. The designed sensor achieves a sensitivity of 1600 nm/RIU (or 938 °/RIU) and is analyzed for its full-width at halfmaximum and quality factor (Q), with the sensor's Q value reaching 8000 /RIU (or 13595 /RIU). Through manufacturing error analysis, it was found that the designed sensor has good mechanical robustness, is easy to manufacture, and is also easy to integrate. The results show that the LiNbO 3 nonlinear tunable material has great application prospects in the field of refractive index sensors.

Design and optimization of two-dimensional porous lithium niobate grating birefringent Bloch surface wave sensor with high sensitivity and quality factor

“…22 Therefore, in recent years, BSW sensors based on the DBR have attracted attention from researchers. 23 The literature also suggests that introducing a top dielectric defect layer to BSW sensors can effectively enhance their performance. 24 Over the past few decades, lithium niobate (LiNbO 3 ) has been extensively studied as a multifunctional crystal material.…”