Ahead of Print article · Journal article
Compact dual-strain sensitivity polymer optical fiber grating for multi-parameter sensing
In this paper, two configurations are presented for simultaneous measurement of strain and temperature by reducing the cross-section area in small regions of the fiber where the Bragg gratings were inscribed, to achieve dual sensitivity to strain and handle the cross-sensitivity to temperature of a single grating.
Each configuration used a single Bragg grating inscribed in a 2-ring undoped poly (methyl methacrylate) microstructured polymer optical fiber (mPOF) with a pulsed Q-switched Nd:YAG laser system. To reduce the cross-section area, a femtosecond laser system was used to remove portions of the mPOF, creating micromachined slots in the fiber, with different lengths for each configuration.
The result was the appearance of a second peak when strain is applied, with a higher strain sensitivity. The thermal, humidity and refractive index response of these gratings were analyzed, revealing a thermal sensitivity almost twice the value of a common Bragg grating inscribed in the same mPOF. The maximum root mean square errors obtained when both strain and temperature are applied in these grating devices were 52 με% and 0.675 °C, respectively.
These results show that the method used to produce these devices could be a suitable and reliable option to fabricate very compact sensors to simultaneously measure strain and other parameters, such as temperature. Moreover, these devices may be used as phase-shift gratings since the position of the reflective peaks and their relative spectral separation may be modulated by applying strain to the optical fiber.
Language: | English |
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Publisher: | IEEE |
Year: | 2021 |
Pages: | 2230-2240 |
ISSN: | 07338724 and 15582213 |
Types: | Ahead of Print article and Journal article |
DOI: | 10.1109/JLT.2020.3046077 |
ORCIDs: | 0000-0002-6080-089X , 0000-0001-7900-0422 , 0000-0003-0736-5849 , 0000-0002-8596-5092 , Woyessa, Getinet , 0000-0002-6002-1060 , 0000-0001-9129-3539 and Bang, Ole |
Fiber lasers Gratings Laser beams Optical fibers Sensitivity Strain