Elliptical photonic crystal fiber sensor for multi-function detection based on surface plasmon resonance

In the paper, we propose an elliptical photonic crystal fiber sensor with an open ring channel, which could enhance the sensor performance. Gold is employed as the plasmonic material and coated on open ring channel. Using the finite element method, the wavelength sensitivity, the amplitude sensitivity, and the optical spectrum leakage from the fiber core to the sample channels are examined, and the influence of structural parameters on the sensor performance is investigated. The numerical results show that the proposed sensor exhibits a wide detection range of the refractive index (RI) from 1.20 to 1.40, the maximum wavelength sensitivity is 21,000 nm/RIU, where RIU is the RI unit, and the maximum amplitude sensitivity of 455.45 RIU⁻¹ is obtained for RI of 1.33. Moreover, the feasibility of the multi-function detection to identify fluorine-containing organics, glucose concentration, and pathogens in water is also numerically investigated.