Simultaneous measurement of refractive index and temperature based on surface plasmonic resonance and mode coupling in a D-shaped hole-assisted dual-core fiber

A dual-parameter sensor based on a hybrid sensing mechanism of surface plasmon resonance (SPR) and mode resonance coupling in a D-shaped hole-assisted dual-core fiber (HADCF) is proposed and experimentally demonstrated. The D-shaped HADCF with Au film is used to excite the SPR for refractive index (RI) measurement, while the mode resonance coupling between the center core and suspended core of the HADCF is used for temperature measurement without RI crosstalk. The measured RI and temperature sensitivities of the sensor are 2907.31 nm/RIU and 2.86 nm/°C, respectively. Due to the advantages of compact size and temperature compensation capability, the proposed sensor has great potential for application in the field of biochemical analysis.