Fig. 1. Schematic of optical fiber gas sensor

Fig. 2. (a) SEM image of the side surface of the thin-core fiber coated with Cu-deposited WS2 film; (b) EDX image for Cu-deposited WS2-coated fiber

Fig. 3. Transmission spectrum of the thin-core fiber coated with Cu-deposited WS2 film

Fig. 4. Spectral response of the sensor in various volume fractions of hydrogen sulfide

Fig. 5. (a) Fitted line of the wavelength shift; (b) dynamic response of the hydrogen sulfide sensor

Fig. 6. Selectivity for nitrogen, carbon dioxide, oxygen and hydrogen sulfide