Dual-core photonic crystal fiber based surface plasmon resonance for refractive index and temperature sensing and polarization filtering

Abstract A dual-core photonic crystal fiber (PCF) based surface plasmon resonance (SPR) sensor for measuring refractive index (RI) and temperature sensing and polarization filtering performance, is presented in this paper. The proposed sensor’s cladding upper polished surface was coated with a gold film for refractive index sensing (RI) while lower polished surface with a composite film of silver and polydimethylsiloxane (PDMS) for temperature sensing. Proposed sensor was designed and simulated using finite element method (FEM) through commercially available Comsol Multiphysics software. Wavelength sensitivity of 18400 nm/RIU along with resolution of 5.43 × 10 −6 RIU and amplitude sensitivity of 150.74 RIU −1 were obtained for core 1 as RI sensing, while wavelength sensitivity of 12.0 nm °C −1 along with resolution of 8.33 × 10 −3 °C for core 2 as temperature sensing. It has a maximum loss of 30822 dB m −1 towards Y-polarization which makes it ideal for polarization filtering, as Y has a higher loss than X-polarization. An extinction ratio (ER) of −92.31 dB at a transferring length of 3 mm was obtained showing its polarization filtering capabilities. Overall results indicate that our sensor is highly sensitive for both RI and temperature sensing and expected to perform better in polarization filtering performances. Its wide detection range in RI combined with temperature sensing increases its potential applications in the medical, chemical, environmental, and biosensor detection industry.