Orthogonal-Sided Polished Microstructured Optical Fiber-Based SPR Sensor for Simultaneous Measurement of Temperature and Refractive Index

Abstract

We propose a concept of orthogonal-side polished microstructured optical fiber (MOF)-based surface plasmon resonance (SPR) sensor to implement the simultaneous sensing for two parameters. Two feasible structures, L-shaped MOF based and rectangular MOF based SPR sensors are investigated theoretically, which can support x-and y-polarized resonance peaks that can be used to measure and separate variations of the temperature and refractive index (RI). Our results show that the temperature coefficients (KTx and KTy) are 8 pm/°C and 6 pm/°C, and the RI coefficients (Knx and Kny) are 1470 nm/RIU and 1570 nm/RIU, for the L-shaped MOF-SPR sensor, while the KTx and the KTy are 10 pm/°C and 8 pm/°C, the Knx and Kny are 1460 nm/RIU and 1500 nm/RIU, for the rectangular MOF-based SPR sensor. Moreover, these coefficients can be further improved by choosing the appropriate structure parameters. The proposed SPR sensors with the advantages of simultaneously measuring two parameters and no need to be filled with the sensing media are expected to be more competitive in the MOF-based SPR sensor field.