Fig. 1. Sensor structure diagrams. (a) Sensor diagram; (b) SCF microscope image

Fig. 2. Schematic diagram of cross section of seven-core optical fiber

Fig. 3. Light field distributions under different cone diameters. (a) D=60 µm; (b) D=50 µm; (c) D=40 µm

Fig. 4. Reflection spectra under different sample diameters

Fig. 5. Sample reflection spectrum and spatial spectrum diagram. (a) Sensor reflection spectrum with L₂=15.6 cm; (b) FFT of measured spectrum

Fig. 6. Curvature experimental device

Fig. 7. Curvature experiment results. (a) Spectral drifts under different curvatures; (b) data fitting result

Fig. 8. Repeated experiment results

Fig. 9. Sensitivity comparison

Fig. 10. Temperature experiment results. (a) Wavelength drifts under different temperatures; (b) data fitting result