Cascaded tilted fiber Bragg grating for enhanced refractive index sensing Project supported by the National Natural Science Foundation of China (Grant Nos. 61775182 and 61505165) and Marie Skłodowska-Curie Individual Fellowships in the European Union’s Horizon 2020 Research and Innovation Programme (Grant No. 660648). |
(color online) (a) Spectral evolution of the cascaded TFBG with the SRI change, and (b) the extracted wavelengths of the core mode and cut-off mode resonances versus the SRI. |