Intensity-modulated acceleration sensor based on chirped-fiber grating

A novel acceleration sensor based on a chirped-fiber Bragg grating( CFBG) has been proposed. It is mainly constituted by a rectangular cantilever beam sensing mechanism, a fiber optic spectrometer and a photodetector(PD). The expression of relationship between the acceleration and the bandwidth is derived. The acceleration can be obtained by measuring the bandwidth and voltage of the PD. The experimental results show that the reflection spectrum bandwidth and voltage of the PD are insensitive to temperature changes within the measuring range, there is a good linear relationship between the bandwidth of the reflection spectrum and the measured acceleration within a large range up to 0~700 m/s2, but the reflected optical power succeeds only below 350 m/s2 due to the decay in reflectivity when the bandwidth of the FBG is broadened significantly. The achieved sensitivities are 0.005 6 nmm-1s-2and 0.785 6 mVm-1s-2 for bandwidth and optical power measurements, respectively.