SrAl₂O₄: Eu²+, Dy³+ Fluorescent Tapered Fiber Sensor for Simultaneous Temperature and Pressure Measurement

This study proposes a self-powered optical sensor based on SrAl₂O₄: Eu²⁺, Dy³⁺ fluorescent particles for simultane-ous temperature and pressure detection. The sensor is fabri-cated by embedding conical optical fibers into a PDMS matrix doped with SrAl₂O₄: Eu²⁺, Dy³⁺ luminescent material. Compared to planar optical fibers, the tapered optical fiber increases the effective area for fluorescence collection, improving light cou-pling efficiency by 34%. Experimental validation results show an average temperature sensitivity of -0.553ms°C⁻¹ and a pressure sensitivity of 111 pm/Pa. The sensor has a maximum tempera-ture resolution of 0.11°C and a maximum pressure resolution of 11 PA. The sensor demonstrates excellent pressure sensing capability with a loading response time as fast as 137 ms. Additionally, the sensor operates on a cross-sen-sitivity matrix to simultaneously demodulate temperature and pressure sensing. It addresses the cross-sensitivity challenges in passive multi-parameter sensing while eliminating the need for an external power source, offering supe-rior linear response, stability, and repeatability. In the future, this sensor is expected to find widespread application in biochemistry, industrial production, and environmental science and technology.