Dual-Parameter Surface Plasmon Resonance Sensor for Simultaneous Detection of Humidity and Temperature Based on Cascaded PVA-GO Composite Film and PDMS Film

A surface plasmon resonance (SPR) sensor based on a polyvinyl alcohol-graphene oxide (PVA-GO) composite film and a polydimethylsiloxane (PDMS) film was proposed for simultaneous measurement of relative humidity (RH) and temperature. The SPR effect was excited by an MMF-SMF-MMF cascaded structure coated with Ag film, and one channel was excited by coating PVA-GO film on its surface for RH sensing, while the other channel was excited by coating PDMS film is used for temperature measurement. The experimental results show that the RH sensitivity of the sensor is 0.507 nm/% RH, and the temperature sensitivity is −3.27 nm/°C. The proposed sensor offers the advantages of compact structure, low cost, and stability and is suitable for fields that require simultaneous measurement of temperature and RH, such as agricultural storage, industrial production, and weather forecasting.