Experimental Study of Dual-Parameter SPR Sensor With Integrated Sensing Channel

In order to meet the actual requirements for sensor miniaturization and integration, we propose a compact dual-parameter surface plasmon resonance (SPR) fiber sensor, which can simultaneously measure the refractive index (RI) and temperature of liquid. The sensor is composed of input–output couplers and two sensing arms. The no-core fibers (NCFs) and microstructured optical fiber (MOF) with deposited films are used as input–output couplers and sensing arms, respectively. One sensing arm is the MOF with silver film for RI measurement, and another is that with silver film and polydimethylsiloxane (PDMS) for temperature measurement. Numerical simulation results show that its cladding mode is more advantageous in stimulating the SPR effect. Experimental results demonstrate that the maximum sensitivity of liquid RI is 4139 nm/RIU in the range of 1.333–1.365, and that of liquid temperature is 4.7 nm/°C in the range of 20 °C–70 °C. The compact structure makes the proposed sensor unique and has a promising application in RI and temperature monitoring.