Highly Sensitive Multimode-Single-Mode-Multimode Optical Fiber SPR Refractive Index Sensor with GaSe Nanosheets

AbstractIntroducing a two-dimensional material Gallium selenide (GaSe) for the sensitization for the first time, a novel multimode-single-mode-multimode fiber surface plasmon resonance (SPR) sensor with the gold (Au)-GaSe structure was designed and fabricated. GaSe has ultrahigh carrier mobility and exhibits more excellent optical properties that can strengthen the surface electric field strength and increase the sensitivity significantly. The simulation model is constructed by the finite element method and the optimal film thicknesses are obtained. The simulation results show that the introduction of GaSe enhances the electric field strength on the gold film surface and has great potential to enable sensors with higher sensitivity. The experimental results indicate that when the thicknesses of both Au film and GaSe nanofilm are set to 50  nm, the sensitivity is the highest, 6167.97 nm/RIU with the refractive index (RI) range from 1.33303 to 1.37340, three times that of the Au film sensors, and the figure of merits (FOM) reaches 34.41 RIU−1. Stability tests demonstrate that the sensor has excellent stability within several hours. The proposed sensor has promising applications in the fields of biosensing and medical detection with its extremely high sensitivity and good stability.
Source: Plasmonics - Category: Biomedical Science Source Type: research