A High-Performance Nano-Refractive Index Sensor Structure Based on Fano Resonance

Optical sensors have a series of advantages, such as anti-interference, fast response, low power consumption, etc. Due to the diffraction limit, optical devices cannot be integrated on a large scale. spp can break through the limitations of traditional optical diffraction limits and manipulate light in the sub-wavelength range. Greatly advance the integration of optical devices. In this paper, a novel nano-sensor structure is proposed, which consists of an MIM waveguide with double rectangles and an annular cavity with embedded stubs. The sensing characteristics are simulated and analyzed by finite element method. In addition, we also analyze the triggers of the Fano resonance line and optimize it by adjusting the parameters. The maximum sensitivity is 1990 nm / RIU, and the advantage value is 63.2. This structure has broad application prospects in sensors in biomedicine and temperature detection.