Reverse drift and restraining of centre-wavelength reflected by tensing fiber Bragg grating

Because of the different elastic modulus between the core and the cladding of the fiber Bragg grating (FBG), a reverse drift of the center-wavelength reflected by a tensing FBG under high load will appear, which would seriously affect the measurement precision and range of a stress sensor based on FBG. The experiment results show that, by peeling off a small section of the cladding at the fixing end of the FBG and fixing both the bared section and part of the contiguous fiber with coating together, the reverse drift of the reflected center-wavelength can be controlled under 10^-3 nm. In addition, the tunable range of the stress sensor will be effectively enhanced and the linearity will be kept better. The experiment results are in accordance with the theoretical calculation.