| Download | - View final version: Accurate measurements of a wavelength drift in high-temperature silica-fiber Bragg gratings (PDF, 855 KiB)
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| DOI | Resolve DOI: https://doi.org/10.3390/metrology1010001 |
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| Author | Search for: Dedyulin, Sergey1ORCID identifier: https://orcid.org/0000-0003-3525-2980; Search for: Timakova, Elena1; Search for: Grobnic, Dan2; Search for: Hnatovsky, Cyril2; Search for: Todd, Andrew D. W.1; Search for: Mihailov, Stephen J.2ORCID identifier: https://orcid.org/0000-0002-6144-0937 |
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| Affiliation | - National Research Council of Canada. Metrology Research Centre
- National Research Council of Canada. Security and Disruptive Technologies
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| Format | Text, Article |
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| Subject | fiber Bragg grating; wavelength drift; pressure-controlled heat pipe |
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| Abstract | Fiber Bragg gratings (FBG) are extensively used to perform high-temperature measurements in harsh environments, however the drift of the characteristic Bragg wavelength affects their long-term stability resulting in an erroneous temperature measurement. Herein we report the most precise and accurate measurements of wavelength drifts available up to date on high-temperature FBGs. The measurements were performed with a set of packaged π-phase-shifted FBGs for high wavelength resolution, in caesium and sodium pressure-controlled heat pipes for stable temperature environment and with a tunable laser for stable wavelength measurements with a 0.1 pm resolution. Using this dataset we outline the experimental caveats that can lead to inconsistent results and confusion in measuring wavelength drifts, namely: influence of packaging; interchangeability of FBGs produced under identical conditions; birefringence of π-phase-shifted FBGs; initial transient behaviour of FBGs at constant temperature and dependence on the previous thermal history of FBGs. In addition, we observe that the wavelength stability of π-phase-shifted gratings at lower temperature is significantly improved upon by annealing at higher temperature. The lowest value of the wavelength drift we obtain is +0.014 pm·h⁻¹ at 600 °C (corresponding to +0.001 °C·h⁻¹) after annealing for 400 h at 1000 °C, the longest annealing time we have tried. The annealing time required to achieve the small drift rate is FBG-specific. |
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| Publication date | 2021-04-14 |
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| Publisher | MDPI |
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| Licence | |
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| In | |
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| Language | English |
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| Peer reviewed | Yes |
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| Export citation | Export as RIS |
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| Report a correction | Report a correction (opens in a new tab) |
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| Record identifier | 5818ae3c-7d6e-4276-b142-0eee282e1881 |
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| Record created | 2021-04-26 |
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| Record modified | 2021-04-26 |
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