Fig. 1. Schematic of bending state of fiber-optic with coating

Fig. 2. Curves of fiber-optic bending loss with bending radius at different temperatures

Fig. 3. Local magnification of three loss peaks in Fig. 2. (a) Bending radius is 7.7 mm; (b) bending radius is 9.1 mm; (c) bending radius is 10.9 mm

Fig. 4. Curves of fiber bending loss with temperature at different bending radii

Fig. 5. Curve fitting results of loss with temperature at 9.15 mm bending radius. (a) Linear fitting and polynomial fitting curves; (b) fitting residuals of two fitting methods

Fig. 6. Preparation process of fiber-optic temperature sensor

Fig. 7. 1060-XP fiber-optic sensor with polyimide coating

Fig. 8. Schematic of fiber-optic macrobending temperature sensor

Fig. 9. Curve of fiber-optic macrobending loss with temperature at 9.15 mm bending radius. (a) Temperature range is -20--100 ℃; (b) temperature range is 0--80 ℃

Fig. 10. Stability test results of sensor at 9.15 mm bending radius and 90 ℃ temperature