Fig. 1. Schematic diagram of the sensor structure

Fig. 2. Model of ultra-small GRIN fiber probe

Fig. 3. Pressure stimulation results of the MEMS sensitive membrane

Fig. 4. Relationship between form and position

Fig. 5. Development process of ultra-small GRIN optical fiber lens

Fig. 6. Photos of the MEMS film

Fig. 7. Manufacturing steps of the sensor

Fig. 8. Image of the sensor head

Fig. 9. Sensor performance detection model based on SS-OCT demodulation system

Fig. 10. Performance test system of MEMS optical fiber acoustic sensor

Fig. 11. Single frequency test under 300 Hz acoustic frequency

Fig. 12. Single frequency response spectrogram

Fig. 13. Test under 100 Hz and 300 Hz mixed frequency

Fig. 14. Frequency spectrum of dual-frequency signal

Fig. 15. Frequency spectrum of tri-band signal under 1 kHz，2 kHz and 3 kHz mixed frequency

Fig. 16. Frequency response characteristic of the sensor

Fig. 17. Acoustic pressure response performance of the optical fiber acoustic pressure sensor

Fig. 18. Frequency spectrum without signal input