The spectral linewidth from two cross-correlated fiber Bragg gratings (FBGs) are interrogated and characterized using a delayed self-homodyne method for fiber strain sensing. This approach employs a common higher frequency resolution instead of wavelength. A sensitivity and resolution of 166 MHz/με and 50 nε were demonstrated from 4 GHz spectral linewidth characterization on the electric spectrum analyzer. A 10 nε higher resolution can be expected through random noise analyses when the spectral linewidth from two FBG correlations is reduced to 1 GHz. Moreover, the FBG spectrum is broadened during strain and experimentally shows a 0.44 pm/με sensitivity, which is mainly caused by the photo elastic effect from the fiber grating period stretch.
ASJC Scopus subject areas
- Analytical Chemistry
- Atomic and Molecular Physics, and Optics
- Electrical and Electronic Engineering
Hsu, S. H., Chuang, K. W., Chen, C. S., Lin, C. Y., & Chang, C. C. (2017). Two interrogated FBG spectral linewidth for strain sensing through correlation. Sensors (Switzerland), 17(12), . https://doi.org/10.3390/s17122837