Tilted fiber Bragg grating (TFBG) shows various advantages in sensing parameters such as, strain, temperature and twist angle. In particular, multiple data collected from cladding modes of TFBG provide a multi-functional modality. According to this feature, a temperature-independent strain sensor and a high sensitivity twist sensor based on TFBG are introduced in this thesis.
The relative wavelength shifts of P and S polarized spectra are utilized in analyzing strain sensors based on their strong temperature-independent characteristics. Linear experimental results which relate to the
wavelength separation from the Bragg mode resonance are presented. Meanwhile, sensitive amplitude variations with respect to the strain applied to TFBG are also evident.
Moreover, TFBG shows high sensitivity to twist angle due to its unique structure. The sensitivity of Polarization-dependent loss (PDL) presents an obvious contrast to that of insertion loss; the comparisons are described experimentally.