Polymer Optical Fiber Bragg Gratings in CYTOP Fibers for Angle Measurement with Dynamic Compensation.
This paper demonstrates the use of polymer optical fiber Bragg gratings (POFBGs) for angle measurements over a range of different oscillatory frequencies. The POFBGs are inscribed in low-loss, cyclic transparent amorphous fluoropolymers (CYTOP) and are imprinted using the direct-write, plane-by-plane femtosecond laser inscription method. As the polymer has a viscoelastic response and given that the Young's modulus depends on the oscillatory frequency, a compensation technique for sensor frequency cross-sensitivity and hysteresis is proposed and verified. Results show that the proposed compensation technique is able to provide a root mean squared error (RMSE) reduction of 44%, and a RMSE as low as 2.20° was obtained when compared with a reference potentiometer. The hysteresis reduction provided by the proposed technique is 55%, with hysteresis <0.01. The results presented in this paper can pave the way for movement analysis with POFBG providing higher sensitivity and low hysteresis over a large range of motion frequencies.
['Leal-Junior|Arnaldo|A|0000-0002-9075-0619', 'Theodosiou|Antreas|A|0000-0002-5912-9138', 'Díaz|Camilo|C|', 'Marques|Carlos|C|0000-0002-8596-5092', 'Pontes|Maria José|MJ|', 'Kalli|Kyriacos|K|0000-0003-4541-092X', 'Frizera-Neto|Anselmo|A|0000-0002-0687-3967']
polymer optical fiber fiber Bragg gratings CYTOP hysteresis curvature sensor