Fig. 1. Diagram of strain sensing system based on optical frequency domain reflectometer

Fig. 2. Structure and packaging diagrams of shape sensor. (a) Structure diagram of shape sensor; (b) schematic diagram of packaging device (inset is enlarged view of substrate-optical fiber positioning part)

Fig. 3. Residual stress monitoring experiment device for curing of different glues

Fig. 4. Monitoring results of fiber optic residual stress during curing process of different adhesives. (a) Monitoring results of residual stress during curing of No.1 adhesive; (b) change of residual stress with time when three glues are cured

Fig. 5. Monitoring results of residual stress of sensor package solidification. (a) Accumulation and distribution of residual stress in packaging area; (b) variation of residual strain with time at a certain point in packaging area

Fig. 6. 3D shape reconstruction of shape sensor. (a) Keep shape sensor straight; (b) bending deformation of shape sensor; (c) reconstructed three-dimensional shape of sensor