Fig. 1. Fabrication of FP micro-cavity. (a) Schematic diagram of femtosecond laser processing; (b) microscope diagram of femtosecond laser inscribed line; (c) FP microbubble

Fig. 2. Physical diagram of sensor. (a) Sensor before coating; (b) sensor after coating; (c) GQDs-PVA measured by SEM

Fig. 3. Initial reflectance spectrum and spatial spectrum of sensor. (a) Initial reflectance spectrogram; (b) spatial spectrum

Fig. 4. Schematic diagram of sensor optical path

Fig. 5. Diagram of experimental setup

Fig. 6. Reflection spectrum variation diagram and linear fitting diagram of strain experiment. (a)-(c) Reflection spectrum variation diagram; (d)-(f) linear fitting diagram

Fig. 7. Reflection spectra of temperature test before coating

Fig. 8. Reflectance spectrum variation diagram and linear fitting diagram of temperature experiment. (a)-(c) Reflection spectrum variation diagram; (d)-(f) linear fitting diagram

Fig. 9. Reflectance spectrum variation diagram and linear fitting diagram of humidity experiment. (a)-(c) Reflection spectrum variation diagram; (d)-(f) linear fitting diagram