Theoretical design of high-dual-sensing-performance sensors based on a magnetoplasmonic nanostructure

The ability to sense multiple parameters simultaneously is essential for developing intelligent and adaptive sensing systems in dynamic environments. In this work, we theoretically design a multilayered magneto-plasmonic structure that exploits the transverse magneto-optical Kerr effect (TMOKE) for high-precision dual-parameter sensing. The proposed configuration-comprising hexagonally arranged Au nanorods, a continuous Au film, a cerium-substituted yttrium iron garnet (Ce:YIG) layer, and an additional Au layer on a SiO₂ substrate-enables the detection of refractive index variations as functions of both the incident angle and wavelength. Remarkably, the structure exhibits an ultra-narrow TMOKE bandwidth of about 0.06 nm and an exceptional refractive index sensitivity of 549.3 nm RIU^-1, leading to a figure of merit exceeding 9 × 10³/RIU. These findings demonstrate a substantial improvement over previous designs and underscore the promise of the proposed structure for next-generation gas-sensing technologies and multifunctional optical detection systems.