Fig. 1. Schematic diagram of the PS-FBG inscription process.

Fig. 2. Schematic diagram of the designed PS-FBG.

Fig. 3. (a) FBG and trace image observed in CCD and (b) optical microscope image of the fiber end face.

Fig. 4. Spectrum of the PS-FBG at different times during the corrosion process: (a) 14 min, (b) 17 min, (c) 21 min, and (d) 24 min.

Fig. 5. Reflection spectra varying with the refractive index.

Fig. 6. Linear relationship between the wavelength and refractive index of the phase shift peak (red line). Linear relationship between the intensity and refractive index of the phase shift peak (blue line).

Fig. 7. Reflection spectra of the microchannel PS-FBG in distilled water at different temperatures.

Fig. 8. Linear relationship between the wavelength and temperature of the three extreme points.