Highly sensitive PCF-SPR sensor for simultaneous and independent sensing of refractive index and temperature

Refractive index (RI) is an important index to determine the composition of a substance, however, it is affected by temperature changes. Therefore, it is of great significance to design a sensor in which temperature variation will not affect the measurement of RI. In this paper, a double D-shaped photonic crystal fiber based on surface plasmon resonance (PCF-SPR) sensor is proposed to realize simultaneous and independent sensing of RI and temperature. The results show that the maximum sensitivity of the proposed sensor reaches 32,100 nm/RIU and 5.9 nm/degrees C for RI and temperature, respectively. In addition, the changes of the air hole radius and the polishing depth will not cause the drift of the resonant wavelength. This advantage is conducive to fabricate a PCF-SPR sensor with high fault tolerance rate and lower production costs in practical process. The paper provides a reference for developing a high-sensitivity and multi-parameter measurement sensor used in water pollution monitoring and bio-sensing.