Two Kinds of Liquid Crystal Filled PCFs Temperature and RI Sensors Based on SPR

We propose two novel kinds of liquid crystal (LC) filled D-shape photonic crystal fibers (PCFs) to realize the simultaneous measurement of refractive index (RI) and temperature. The gold film is selected as the plasmonic metal and coated on the D-shaped air hole of the PCF to excite the surface plasmon resonance (SPR). According to the position where the RI liquid is filled in the air hole, the PCFs are named type-1 and type-2. Simulation results show that the proposed sensors have good temperature and RI sensing performance in the detection ranges of 15 °C–50 °C and 1.47–1.55, respectively. For the type-1 sensor, the temperature and RI sensitivities of the ${y}$ -polarized core mode are 2.7 nm/°C and 2200 nm/RIU, respectively, and the corresponding linear fitting degrees are 0.95756 and 0.98771. The temperature and RI sensitivities of type-2 are 3.2 nm/°C and 2567 nm/RIU, respectively, and the corresponding linear fits are 0.93135 and 0.98771. The designed dual detection sensors have a great potential and are expected to be applied in environmental, biological, and biochemical sensing.