Nanometal ring-array LSPR fiber sensor based on the perfectly matched layer and perfectly reflecting boundary

To reduce the error between actual operations and numerical simulations, thereby enabling effective design parameters to be obtained during the sensor production process and increasing the precision of simulated results, we integrated theories relevant to the perfectly matched layer and perfectly reflecting boundary condition with the finite element method and eigenmode expansion method. In addition, the modified simulation method was used to design and research a high-performance nanometal ring-array localized surface plasmon resonance (LSPR) sensor, comprising single-mode fibers (SMFs) and nanometal ring arrays. The existence of LSPR waves is the primary reason that determines whether LSPR sensors exhibit high sensitivity; thus, we examined the ability of the sensor structure to trigger LSPR waves by using the electric field Er of the core mode HE11 on the optical fiber. After employing the relevant algorithms, the resulting images demonstrated the excitation of the LSPR. This nanometal ring-array LSPR fiber sensor is advantageous because of its short length (393.59788 μm), high resolution (approximately −90 dB), and high sensitivity (approximately 38,600 nm/RIU).