Mehta, S.Nakul Nayak, V.B.Singh, M.2026-02-042024IEEE Sensors Journal, 2024, 24, 8, pp. 12304-123111530437Xhttps://doi.org/10.1109/JSEN.2024.3373907https://idr.nitk.ac.in/handle/123456789/21176This study introduces a novel application of a plasmonic microdisk resonator as a highly sensitive sensor for detecting methanol vapor. Leveraging the inherent advantages of plasmonic nanostructures, the microdisk resonator demonstrates a remarkable capability to detect minute concentrations of methanol. In this work, we modeled a novel 3-D porous-silicon (p-Si)-based hybrid plasmonic aperture-coupled microdisk resonator (HPACMR) with specific dimensions and porosity to optimize the sensitivity toward methanol vapor detection. The resonator's design incorporates a thin layer of copper on a dielectric microdisk, creating a plasmonic cavity that supports localized surface plasmon resonances. Finite element method-based simulations predict strong interactions between the resonator's plasmonic field and methanol molecules, leading to detectable shifts in the resonant frequency. By tuning the layout dimensions and p-Si properties, we achieved an altitudinous sensitivity of 569.52 nm/RIU and a Q-factor of nearly 370. The sensors' miniature footprint and potential for integration into portable devices make it an attractive candidate for field-deployable applications. © 2001-2012 IEEE.Finite element methodMethanolNatural frequenciesOptical resonatorsPlasmonicsPorous siliconQ factor measurementRefractive indexSurface plasmon resonanceDisk resonatorMethanol vaporsMicro-disk resonatorMicrodisksNovel applicationsSensitive sensorsSensitivitySilicon photonicsSilicon-based