Fig. 1. Optical model of sensor

Fig. 2. Fabrication platform of sensor and simulation analysis of waveguide structures in Solidworks

Fig. 3. Manufacturing process of sensor

Fig. 4. Interference spectra and fast fourier transform spectra of sensor

Fig. 5. The experimental setup for humidity sensing

Fig. 6. Interference spectra and linear fitting during humidity variations

Fig. 7. Repetitiveness and stability test

Fig. 8. Temperature response curve of optic fiber humidity sensor

Fig. 9. Experimental setup for breathing monitoring system

Fig. 10. Real-time deep breathing monitoring