Surface Plasmon Resonance Temperature Sensor Based on Coated Chalcogenides

In this article, we proposed a temperature sensor based on a multimode-thinned-core-multimode fiber (MMF-TCF-MMF) structure employing surface plasmon resonance (SPR). The sensor was fabricated by coating a silver (Ag) film and a thin film of chalcogenide materials on the surface of an optical fiber, followed by encapsulating the sensing region with polydimethylsiloxane (PDMS). The effects of five materials—MoS2, WS2, GeSe, Cr2S3, and In2Se3—on the temperature performance of sensors through optimization and comparative analysis were investigated. Experiments have demonstrated that the presence of chalcogenides enhances the absorption of light energy, thereby exciting a stronger SPR phenomenon. Within the temperature range of $30~^{\circ }$ C– $120~^{\circ }$ C, the sensor coated with a GeSe thin film exhibits a significantly higher temperature sensitivity compared to other materials, reaching up to 2.194 nm/°C, which is a 45.0% increase compared to the sensor coated only with Ag. The proposed chalcogenide temperature sensor features a wide temperature detection range, fast response speed, high sensitivity, simple structure, low cost, and excellent stability, making it highly significant in the field of environmental temperature detection.