Research on sensitive characteristics of tilted fiber grating sensors

Abstract

In recent years, the optical fiber sensing technology has attracted social more and more attention because it has advantages of strong anti-interference ability, corrosion resistance and high sensitivity. So the research of the optical fiber sensing technology has become a hot issue for researchers. Fiber Bragg grating(FBG) sensing is a kind of optical fiber sensing, and the transmission spectrum or reflection spectrum is affected by the change of external environment. The research of this topic is tilted fiber Bragg gratings(TFBG), there are core modes and a large number of cladding modes in the transmission spectrum of TFBG sensor, which will change with the change of the external environment, so it is of great significance to study its transmission spectrum with the external changes.Firstly, the temperature and refractive index sensing performance of TFBG by Optigrating. Then we measures the temperature sensing, refractive index sensing and strain sensing of the TFBG sensor, and the tilt angle is 8°, the period is 530nm, the modulation depth is grater than15dB, and the experimental results are consistent with the simulation results. We obtained that the temperature sensitivity of the TFBG is 10pm/℃ in the measurement range of 20℃-150℃, and the refractive index sensitivity is 3.2pm/% in the range of 0-25%NaCl solution, and the stress sensitivity is 1.593nm/mm in the range of 0-1.2mm tensile length in our experiment. Therefore, the TFBG sensor has important applications in many fields.