High-precision fiber-optic temperature sensor based on Fabry-Perot interferometer with reflective thin-film multilayer structures

An embodiment of a fiber-optic temperature sensor based on a Fabry-Perot interferometer and a scheme for interrogating an experimental sample of the sensor are proposed. The proposed solution makes it possible not to use expensive spectral measuring devices (spectrum analyzer, interrogator). The region of free dispersion and the phase sensitivity of the developed Fabry-Perot interferometer were determined in the temperature range from 20 °C to 590 °C. The accuracy of measuring the ambient temperature is calculated. The long-term stability of the measuring setup at room temperature has been evaluated. The phase shift of the Fabry-Perot interferometer with temperature change was registered. The design of the Fabry-Perot interferometer is implemented using reflective thin-film multilayer structures obtained by stage-bystage electron-beam deposition in vacuum on polished end cleavages of an optical fiber. The interferometer interrogation method is based on the use of a vertical-cavity surface-emitting laser (VCSEL) operating in a pulsed mode. The principle of registering the phase shift of the interferometer with a change in temperature is based on the use of auxiliary modulation of laser radiation along the wavelength due to modulation (periodic change) of the duration of optical pulses. Auxiliary modulation makes it possible to obtain additional harmonic components in the interferometer signal, which are further used in homodyne demodulation to restore the interferometer phase shift signal proportional to the change in the optical path difference between the interferometer mirrors. The design of the high-temperature sensor is based on a Fabry-Perot interferometer the reflecting mirrors of which are five alternating layers of thin films of TiO₂ and Al₂O₃. Based on the results of the temperature experiment, it was concluded that an increase in the ambient temperature leads to a decrease in the free dispersion region of the Fabry-Perot interferometer. The conclusion made is consistent with the theoretical data. According to the results of the experiment, it is shown that the phase sensitivity of the interferometer to temperature changes is 0.94 rad/K. The accuracy of temperature measurements at the 3σ level was 0.017 K. The results of the study may be of great importance in creating systems for monitoring temperatures above 300 °C. The use of such an interferometer makes it possible to carry out high-precision relative temperature measurements.

1. Kashyap R. Fiber Bragg Gratings. San Diego, CA, Academic Press, 1999, 478 p.

2. Meshkovsky I.K., Varzhel S.V., Belikin M.N., Kulikov A.V., Brunov V.S. Thermal annealing of Bragg grating on manufacturing of fiber-optic phase sensor. Journal of Instrument Engineering, 2013, vol. 56, no. 5, pp. 91–93. (in Russian)

3. Liao C.R., Wang D.N. Review of femtosecond laser fabricated fiber Bragg gratings for high temperature sensing. Photonic Sensors, 2013, vol. 3, no. 2, pp. 97–101. https://doi.org/10.1007/s13320-012-0060-9

4. Minkin A.M., Sozonov N.S., Fadeev K.M., Shevtcov D.I. Miniature fiber-optic pressure sensor based on the Fabry–Pérot interferometer. Proc. of the 2nd All-Russian Conference «Optical Reflexometry-2018», 2018, pp. 86–89. (in Russian)

5. Pratt D.J. Optical wavelength sensor. Patent РСТ WO1995020144A1, 1995.

6. Egorova O.N., Vasil’ev S.A., Likhachev I.G., Sverchkov S.E., Galagan B.I., Denker B.I., Semjonov S.L., Pustovoi V.I. A Fabry– Perot interferometer formed in the core of a composite optical fibre heavily doped with phosphorus oxide. Quantum Electronics, 2019, vol. 49, no. 12, pp. 1140–1144. https://doi.org/10.1070/QEL17133

7. Huang C., Xie W., Lee D., Qi C., Yang M., Wang M., Tang J. Optical fiber humidity sensor with porous TiO2/SiO2/TiO2 coatings on fiber tip. IEEE Photonics Technology Letters, 2015, vol. 27, no. 14, pp. 1495–1498. https://doi.org/10.1109/LPT.2015.2426726

8. Agafonova D.S. Fiber optical temperature sensor. Patent RU155334U1, 2015. (in Russian)

9. Egorova O.N., Semjonov S.L., Velmiskin V.V., Yatsenko Yu.P., Sverchkov S.E., Galagan B.I., Denker B.I., Dianov E.M. Phosphatecore silica-clad Er/Yb-doped optical fiber and cladding pumped laser. Optics Express, 2014, vol. 22, no. 7, pp. 7632–7637. https://doi.org/10.1364/OE.22.007632

10. Duan D.W., Rao Y., Hou Y.-S., Zhu T. Microbubble based fiber-optic Fabry-Perot interferometer formed by fusion splicing single-mode fibers for strain measurement. Applied Optics, 2012, vol. 51, no. 8, pp. 1033–1036. https://doi.org/10.1364/AO.51.001033

11. Machavaram V.R., Badcock R.A., Fernando G.F. Fabrication of intrinsic fibre Fabry-Perot sensors in silica fibres using hydrofluoric acid etching. Sensors and Actuators, A: Physical, 2007, vol. 138, pp. 248–260. https://doi.org/10.1016/j.sna.2007.04.007

12. Liu S., Wang Y., Liao C., Wang G., Li Z., Wang Q., Zhou J., Yang K., Zhong X., Zhao J., Tang J. High-sensitivity strain sensor based on in-fiber improved Fabry–Perot interferometer. Optics Letters, 2014, vol. 39, no. 7, pp. 2121–2124. https://doi.org/10.1364/OL.39.002121

13. Ma Z., Pang F., Liu H., Chen Z., Wang T. Air microcavity formed in sapphire-derived fiber for high temperature sensing. Proc. of the 26th International Conference on Optical Fiber Sensors, 2018, pp. WF48. https://doi.org/10.1364/OFS.2018.WF48

14. Terent’ev V.S., Simonov V.A. High-finesse multiple-beam reflection interferometer based on dielectric diffraction structure in a single-mode fiber. Applied Photonics, 2017, vol. 4, no. 2, pp. 107–120. (in Russian)

15. Tertyshnik A.D., Volkov P.V., Gorjunov A.V., Luk’janov A.J. Fibreoptic interference temperature sensor. Patent RU2466366C1, 2012. (in Russian)

16. Bennett J.M., Pelletier E., Albrand G., Borgogno J.P., Lazarides B., Carniglia C.K., Schmell R.A., Allen T.H., Tuttle-Hart T., Guenther K.H., Saxer A. Comparison of the properties of titanium dioxide films prepared by various techniques. Applied Optics, 1989, vol. 28, no. 16, pp. 3303–3317. https://doi.org/10.1364/AO.28.003303

17. Hirsch M., Majchrowicz D., Wierzba P., Weber M., Bechelany M., Jędrzejewska-Szczerska M. Low-coherence interferometric fiber-optic sensors with potential applications as biosensors. Sensors, 2017, vol. 17, no. 2, pp. 261. https://doi.org/10.3390/s17020261

18. Lee D., Yang M., Huang C., Dai J. Optical fiber high-temperature sensor based on dielectric films extrinsic Fabry–Pérot cavity. IEEE Photonics Technology Letters, 2014, vol. 26, no. 21, pp. 2107–2110. https://doi.org/10.1109/LPT.2014.2346622

19. Kireenkov A.Y., Alejnik A.S., Plotnikov M.Y., Mekhrengin M.V. Method of frequency-pulse modulation of a semiconductor laser source of optical radiation for optical interferometric sensors. Patent RU2646420C1, 2018. (in Russian)

20. Kireenkov A.Iu. Fiber-optic interferometric methods for constructing the measuring systems based on a surface-emitting laser. Dissertation for the degree of candidate of technical sciences. St. Petersburg, NIU ITMO, 2017, 155 p. (in Russian)

21. Efimov M.E. Method and equipment for the recording acoustic emission and deformations of a composite graphite-epoxy material based on the analysis of the amplitude-phase characteristics of the signal from a fiber-optic Fabry-Pérot interferometer. Dissertation for the degree of candidate of technical sciences. St. Petersburg, NIU ITMO, 2018, 147 p. (in Russian)

22. Plotnikov M.Y., Volkov A.V. Adaptive phase noise cancellation technique for fiber-optic interferometric sensors. Journal of Lightwave Technology, 2021, vol. 39, no. 14, pp. 4853–4860. https://doi.org/10.1109/JLT.2021.3075781

23. Volkov A.V., Plotnikov M.Y., Mekhrengin M.V., Miroshnichenko G.P., Aleynik A.S. Phase modulation depth evaluation and correction technique for the PGC demodulation scheme in fiber-optic interferometric sensors. IEEE Sensors Journal, 2017, vol. 17, no. 13, pp. 4143–4150. http://dx.doi.org/10.1109/JSEN.2017.2704287

24. Lee C.E., Atkins R.A., Taylor H.F. Performance of a fiber-optic temperature sensor from -200 to 1050°C. Optics Letters, 1988, vol. 13, no. 11, pp. 1038–1040. https://doi.org/10.1364/OL.13.001038

25. Gao H., Jiang Y., Cui Y., Zhang L., Jia J., Jiang L. Investigation on the thermo-optic coefficient of silica fiber within a wide temperature range. Journal of Lightwave Technology, 2018, vol. 36, no. 24, pp. 5881–5886. https://doi.org/10.1109/JLT.2018.2875941