Simulation and Comprehensive Analysis of Fluoride Fiber SPR Sensor With Multilayer Variants of 2D Materials (Graphene and MoS2) Under Optimum Radiation Damping in NIR

Abstract

The performance of multiple variants of fluoride fiber plasmonic sensor is simulated and analyzed under optimum radiation damping (ORD) in terms of coordinated tuning of Ag layer thickness ( $\text{d}_{\mathbf {Ag}}$ ) and near infrared (NIR) wavelength ( $\lambda $ ). The sensor variants are in terms of number of monolayers (N: 1 – 5) of graphene and MoS2. The dispersion relations of all constituent layers along with the transfer matrix method are utilized for sensor simulation. The sensor’s performance is evaluated in terms of figure of merit (FOM) that takes into account the shift and width of fiber power loss resonance curves originating under the plasmonic modulation. Further totality is added to performance evaluation by combining the FOM with signal scattering and power loss ratio factors. The simulation results and their comprehensive analysis indicate that a combination of $\lambda =925.3$ nm, $\text{d}_{\mathbf {Ag}} =48.4$ nm, and MoS2 monolayer can provide considerably enhanced performance in terms of maximum FOM, small light signal scattering (and analyte photodamage), and large power loss ratio (with respect to the reference resonance curve). The FOM achievable with this sensor is 4.5 times better than the previously reported chalcogenide fiber plasmonic sensor under its corresponding ORD. A deeper analysis of the proposed fluoride sensor predicts that even smaller signal scattering (and photodamage) along with nearly identical power loss ratio and FOM can be achieved with the sensor variant based on MoS2 bilayer.