Accurate measurements of a wavelength drift in high-temperature silica-fiber Bragg gratings
| Autor: | Stephen J. Mihailov, Dan Grobnic, Sergey Dedyulin, A. D. W. Todd, Elena Timakova, Cyril Hnatovsky |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2021 |
| Předmět: |
Birefringence
Materials science Silica fiber business.industry 010401 analytical chemistry Physics::Optics wavelength drift 02 engineering and technology pressure-controlled heat pipe 021001 nanoscience & nanotechnology 01 natural sciences Temperature measurement 0104 chemical sciences Annealing (glass) fiber Bragg grating Wavelength Optics Fiber Bragg grating General Materials Science Stochastic drift 0210 nano-technology business Tunable laser |
| Zdroj: | Metrology Volume 1 Issue 1 Pages 1-16 |
| Popis: | 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. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
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