Temperature Independent Tapered Fiber Bragg Grating-Based Inclinometer

A new concept for an optical fiber inclinometer based on tapered fiber Bragg grating (TFBG) is presented. The sensor was characterized by the experimental measurement of the dependence of inclination angle on the spectral response in fluctuating temperature conditions. The research showed that the TFBG made it possible to simultaneously measure both the inclination angle and temperature, and to operate as a temperature insensitive 0°–90° tilt sensor, in a different interrogation regime. Inscription of the FBG in the tapered optical fiber section offered not only sensor miniaturization, but also the possibility of temperature sensing by the fiber section adjacent to the inclination area. Moreover, due to the reflective mode of the TFBG, the sensor offers excellent sensitivity due to the double-loss operation.