Fig. 1. Schematic diagram of droplet-type optical fiber sensor

Fig. 2. Production process for droplet-type optical fiber sensor

Fig. 3. Physical diagram of droplet-type optical fiber sensor

Fig. 4. Experimental setup of droplet-type optical fiber sensor. (a) Schematic diagram; (b) physical diagram

Fig. 5. Output spectrum of droplet-type optical fiber sensor and FFT diagram when volume fraction of isopropyl alcohol is 0.(a) Output spectrum of droplet-type optical fiber sensor; (b) FFT diagram

Fig. 6. Spectra of droplet-type optical fiber VOC sensor based on PDMS

Fig. 7. Linear fitting plot of interference peaks. (a) Peak 1; (b) peak 2; (c) peak 3

Fig. 8. Repeatable experimental results of peak 3. (a) Enlarged spectra; (b) linear fitting plot of four experiments

Fig. 9. Time response of proposed sensor

Fig. 10. Partially amplified spectroscopy of droplet-type optical fiber VOC sensor based on PDMS

Fig. 11. Relationship between interference intensity and VOC concentration at 1526.44 nm and 1539.00 nm