Fig. 1. Fiber structure type: tapered fiber, U-shaped fiber, microstructure fiber, D-shaped fiber

Fig. 2. Optical fiber evanescent wave sensing

Fig. 3. Red shift of interference spectrum for a functionalized tapered optical fiber sensor used to detect Dengue E protein. (a) Without PMMA surface functionalization^[15]; (b) with PMMA surface functionalization^[16]

Fig. 4. Nucleic acid functionalized fiber optic probes^[22]. (a) Schematic illustration of the sandwich-type assembly based Ade detection strategy; (b)calibration curve of Ade

Fig. 5. Schematic diagram of experimental setup used to characterize fabricated sensor^[30]

Fig. 6. Fe₂O₃ nanotube coating micro-fiber interferometer^[32]. (a) Diagrammatic sketch of gas sensing principle for the Fe₂O₃ coated MFI; (b) sectional view for the multi-core fiber

Fig. 7. MIR molecular fingerprint region^[38]

Fig. 8. Evanescent wave biochemical sensing of chalcogenide fibers. (a) FEWS spectra of fed (solid line) and starved (dashed line) mice liver^[41]; (b) human lung cell infrared spectra recorded with the TAS glass fiber^[37]

Fig. 9. DIAFIR company’s product in France: TAS fiber evanescent wave sensor^[42]

Fig. 10. Polymer-coated fiber sensor^[44]. (a)General measurement principle of EWS of the polymer-coated fiber sensor；(b)IR absorption spectra of six concentrations of the p-xylene aqueous solution recorded by coated and uncoated ChG-TF

Fig. 11. SEM picture^[14]. (a) Holes with different pulse energy; (b) hole with 24 mW pulse energy; (c) hole-array channels; (d) linear channels; (e) measured spectral responses at different CH₄ concentrations; (f) absorption peak intensity as a function of CH₄ concentration