Fig. 1. Schematic of FBG imprinted in an SMF by the phase-mask technique with a scanning UV laser beam.

Fig. 2. (a) SEM photo of a single-ring supporting MOF and (b) the pressure response measured using an FBG on this fiber^[15].

Fig. 3. (a) Schematic figure of the fluidic flow sensor based on an FBG written on an SMF and Co2+-doped multimode fibers, and (b) comparison of the flow rates measured by the FBG-based flow sensor and a commercial flowmeter installed in the test rig.

Fig. 4. Schematic figure of FBG sensors installed on the track of railway, where the inset shows the measured strain induced by the wheel.

Fig. 5. Rail track-based FBG sensing network for monitoring of various critical conditions of moving trains^[28]. The 4-digit numbers in blue indicate the commencement year for that project.

Fig. 6. (a) The pulse wave of filter processing in a wrist, (b) the predicted results of SBP, and (c) the predicted results of DBP in the wrist (© [2015] IEEE. Reprinted, with permission from Ref. [25]).