Flexible Optical Fiber Stress/Temperature Dual‐Mode Sensing Based on CaZnOS:Nd,Er

Abstract Mechanoluminescence (ML) and upconversion luminescence (UCL) materials exhibit significant potential in advanced optical sensing applications. However, single‐function luminescent materials often fail to meet the increased complexity and precision demands of modern application scenarios. Here, flexible optical fiber based on ML and UCL dual‐mode luminescence is demonstrated in Ca/SrZnOS: Nd 3+ , Er 3+ , which can be integrated into potential dual‐mode stress and temperature sensing devices. After 4200 cycles of 2 N load, the ML intensity remaines at ≈67% of its initial value. Additionally, such device has a temperature sensitivity of 1.423% K −1 at 273.15 K, with a detection accuracy of 1.1990 °C. The device maintained excellent cycling stability over a broad temperature range (0–80 °C), as evidenced by the unchanged FIR values after 10 cycles. The device demonstrates potential applications in remote stress and temperature monitoring, particularly in high‐temperature, high‐pressure, or hazardous environments, where optical fiber transmission ensures both safety and accuracy.