1. Strain, torsion and refractive index sensors based on helical long period fibre grating inscribed in small-core fibre for structural condition monitoring.
- Author
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Fu, Cailing, Ni, Yi-Qing, Sun, Tong, Wang, Yiping, Ding, Siqi, and Vidakovic, Miodrag
- Subjects
BRAGG gratings ,STRUCTURAL health monitoring ,OPTICAL gratings ,REFRACTIVE index ,PLASTIC optical fibers ,TORSION ,FIBERS ,DETECTORS - Abstract
This study is intended to develop long period fibre grating sensors for potential applications in environmental and durability monitoring of coastal structures. High-quality helical long period fibre gratings (HLPFGs) are inscribed in different types of small-core single mode fibre (SMF) by use of hydrogen-oxygen flame heating technique. A detailed investigation of the effect of core diameter on their transmission spectrum and optimum length of the HLPFG has been pursued. A longer length is required to achieve the same coupling attenuation in a smaller-core SMF than that of a larger-core fibre. The strain, torsion and refractive index (RI) properties of the HLPFG is investigated experimentally to develop a high-sensitivity sensor. The experimental results show that the strain sensitivity could be enhanced by means of employing a larger-core diameter SMF. Moreover, the HLFPGs are also sensitive to the torsion and external RI. Hence, such HLFPGs have great potential for sensing applications. [ABSTRACT FROM AUTHOR]
- Published
- 2021
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