H-shaped structure plastic optical fiber dual-channel SPR sensor for temperature and refractive index

Abstract An H-shaped structure plastic optical fiber (POF) surface plasmon resonance (SPR) sensor was fabricated for dual-channel measurement of refractive index (RI) and temperature. The sensing region with an H-shaped side structure was created on the POF using a hot-pressing method, and a Ag film was deposited on both surfaces of the sensing region to excite SPR. A polydimethylsiloxane film was coated on one of the Ag surfaces as a temperature-sensitive medium, forming the temperature sensing channel, thus realizing dual sensing channels for RI and temperature. Experimental results show that within the RI range of 1.333–1.373 and temperature range of 10 °C–60 °C, the sensor achieves an RI sensitivity of 1594 nm RIU −1 and a temperature sensitivity of −0.74 nm °C −1 . The sensor offers advantages of high sensitivity, compact structure, simple fabrication, low cost, and low crosstalk, making it highly promising for applications in biochemical sensing and biomedical fields.