Temperature-insensitive tilt sensor with strain-chirped fiber Bragg gratings

A novel tilt sensor with three fiber Bragg gratings (FBGs) has been demonstrated. It can detect the magnitude as well as the direction of the inclination from the horizontal direction by measuring the reflected optical powers of the FBGs, whose bandwidths vary with the inclination, directly. The experimental results show that it is insensitive to temperature. The measurement accuracy of +/- 0.13 degrees and resolution of 0.02 degrees have been achieved.