Fig. 1. Preparation of sensing probe. (a) Preparation flow chart; (b) sensing probe and its parameters

Fig. 2. Optical fiber temperature sensing system

Fig. 3. Concentration optimization of rhodamines. Fluorescence spectra of (a) rhodamine B and (b) rhodamine 123; concentration optimization of (c) rhodamine B and (d) rhodamine 123

Fig. 4. Structure parameter optimization of sensing probe. Spectra of temperature (a) raising and (b) dropping; (c) comparison of temperature raising and dropping; optimization of (d) length, (e) outer diameter and (f) fiber insertion ratio

Fig. 5. Response of the sensor to temperature under different environments. Spectra of temperature response in (a) gas, (b) liquid and (c) solid environments; (d) intensity ratios under different environments

Fig. 6. Performance evaluation of the optical fiber temperature sensor. (a) Calibration curve, (b) accuracy, (c) repeatability and (d) stability test results

Fig. 7. Practical application test for the sensor. (a) Natural cooling of hot water; (b) heating process of hand warmer