An Ultra-High-Resolution Bending Temperature Decoupled Measurement Sensor Based on a Novel Core Refractive Index-Like Linear Distribution Doped Fiber

• Main Authors: Fan, L. (Author), Hu, X. (Author), Kong, L. (Author), Wang, Z. (Author), Wu, D. (Author), Zhang, Y. (Author)
• Format: Article
• Language: English
• Published: MDPI 2022
• Subjects: Alumina; Aluminum oxide; bending sensor; Bending sensors; decoupling measurement; Decoupling measurement; Decouplings; Doped fiber; Fiber optic sensors; Fibre-optic sensor; high resolution; High resolution; High sensitivity; Linear distribution; Measurement sensor; Quantum theory; Refractive index; Single mode fibers; Temperature; Temperature measurement; temperature sensor; Temperature sensors; Ultrahigh resolution
• Online Access: View Fulltext in Publisher

 A high-resolution and high-sensitivity fiber optic sensor based on the quasi-linear distribution of the core refractive index is designed and fabricated, which enables decouple measurement of bending and of temperature. First, single-mode fiber doped with Al2O3, Y2O3, and P2O5 was drawn through a fiber drawing tower. The fiber grating was engraved on the fiber by a femtosecond laser. Modeling analysis was conducted from quantum theory. Experimental results show that the bending sensitivity of the grating can reach 21.85 dB/m−1, which is larger than the reported sensitivity of similar sensors. In the high temperature range from room temperature to 1000◦C, the temperature sensitivity was 14.1 pm/◦C. The doped grating sensor can achieve high temperature measurement without annealing, and it has a distinguished linear response from low temperature to high temperature. The bending resolution can reach 0.0004 m−1, and the temperature resolution can reach 0.007◦C. Two-parameter decoupling measurement can be realized according to the distinctive characteristic trends of the spectrum. What’s more, the sensor exhibits excellent stability and a fast response time. © 2022 by the authors. Licensee MDPI, Basel, Switzerland.