Temperature-Insensitive Fiber Bragg Grating Based Tilt Sensor With Large Dynamic Range

We present a novel and simple temperature-insensitive fiber Bragg grating (FBG) based smart tilt sensor. The sensor design is free from any inherent mechanical joints/frictions with a capability to measure magnitude as well as the direction of the inclination. The first design is with a sensitivity of 0.00282 nm/ $^{\circ}$ in a very large dynamic range of ${\pm} 35^{\circ}$ . The sensor response is optimized against design parameters and observed to be completely reversible. Since there is a strain discrepancy on individual FBGs of the first design, a modified design is then proposed for optimization. An excellent sensitivity of 0.0395 nm/ $^{\circ}$ , resolution of 0.013 $^{\circ}$ and accuracy of 0.051 $^{\circ}$ have been achieved. These features along with the freedom to tune the dynamic range, accuracy of measurement and the sensitivity of the proposed sensor to a desired operation range make the proposed sensor of extreme importance for practical engineering applications.