Research on Surface Plasmon Resonance Sensing of Metal Nano hollow Elliptic Cylinder

In this article, a new three-dimensional multi-layered nanoscale elliptical cylinder structure-based surface plasmon resonance sensor is designed, which utilizes the finite difference time domain method and FDTD simulation software for numerical simulation. The top of the structure is an elliptical cylinder array attached to a gold film with nanoholes. The middle layer is a dielectric layer, which can restrict the electromagnetic field. The bottom layer is an Au film and Si substrate. Surface plasmon resonance is excited by a vertically incident plane wave structure, and the incident electromagnetic wave is coupled to local surface plasmon through gold nanoscale elliptical cylinders. By adjusting the relevant structural parameters, the structure’s resonance wavelength and resonance depth can be well adjusted. The optimized sensing structure has a smaller half-width than the traditional solid elliptical cylinder, higher sensitivity, and a larger quality factor. This structure can detect refractive indices in both gaseous and liquid environments, overcome the disadvantage of only being able to sense in a single environment, and provide a new approach for surface plasmon resonance sensing in biology and chemistry.