Cascaded plastic optical fiber based SPR sensor for simultaneous measurement of refractive index and temperature

A cascaded side -polish plastic optical fiber (POF) and FONTEX optical fiber based surface plasmon resonance (SPR) sensor is proposed for simultaneous measurement of refractive index (RI) and temperature. The side -polish POF and FONTEX optical fiber are connected by using the UV glue in a Teflon plastic tube. The SPR phenomenon can be excited at both of the side -polish region and the FONTEX fiber cladding. The polydimethylsiloxane (PDMS) is coated on the side -polish POF to get a temperature sensing channel. Due to the low RI sensitivity of the FONTEX optical fiber, the cascaded fiber sensor can obtain a broader RI measurement range with a low crosstalk. An RI sensitivity of 700 nm/RIU in the RI measurement range of 1.335-1.39 and a temperature sensitivity of-1.02 nm/degrees C measured in deionized water with a range of 20-60 degrees C are obtained. In addition, the cascaded POF based SPR sensor has potential application prospects in the field of biochemical sensing. (c) 2024 Optica Publishing Group under the terms of the Optica Open Access Publishing Agreement