Fabrication of Fiber Bragg Gratings Using Interferometric Methods For Sensing Applications
Peltoniemi, Jesse (2025)
2025
Teknis-luonnontieteellinen DI-ohjelma - Master's Programme in Science and Engineering
Tekniikan ja luonnontieteiden tiedekunta - Faculty of Engineering and Natural Sciences
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Hyväksymispäivämäärä
2025-03-05
Julkaisun pysyvä osoite on
https://urn.fi/URN:NBN:fi:tuni-202503042572
https://urn.fi/URN:NBN:fi:tuni-202503042572
Tiivistelmä
Fiber Bragg gratings (FBGs) are highly sensitive optical components widely used for precise measurements of temperature, strain, and pressure. Their advantages—such as high accuracy, immunity to electromagnetic interference, multiplexing capabilities, and robustness in harsh environments—make them ideal for structural health monitoring, aerospace, and medical sensing applications. In structural monitoring, FBGs detect strain variations in bridges and buildings, providing real-time data to prevent failures, while in medical applications, they enable minimally invasive pressure and temperature sensing for diagnostics and treatment.
This work, conducted at Modulight Corporation, focused on developing and optimizing the FBG fabrication process. All key stages were examined, including pre-inscription, grating inscription mechanisms, design parameter interactions affecting sensor performance, and post-inscription processing and characterization. The developed process demonstrated reliable and consistent FBG fabrication, with scalability and adaptability for diverse industrial applications. Further developments are necessary to optimize the fabrication process for specialized applications, such as single-frequency laser systems.
Additionally, this study evaluated the properties of in-house inscribed large-diameter FBGs for temperature sensing applications. The fabricated FBGs exhibited promising performance, achieving a temperature measurement accuracy of $\sigma_{T'} = 0.55 ^{\circ}$C, closely matching the $0.55^{\circ}$C, the accuracy of a commercial FBG. This similarity in accuracy indicates that the in-house fabricated FBGs can perform at a level comparable to commercially available sensors.
Overall, this work successfully optimized a systematic and reliable FBG fabrication process, which has now been implemented at Modulight Corporation. Furthermore, the results highlight the potential of large-diameter FBGs for robust and precise sensing applications.
This work, conducted at Modulight Corporation, focused on developing and optimizing the FBG fabrication process. All key stages were examined, including pre-inscription, grating inscription mechanisms, design parameter interactions affecting sensor performance, and post-inscription processing and characterization. The developed process demonstrated reliable and consistent FBG fabrication, with scalability and adaptability for diverse industrial applications. Further developments are necessary to optimize the fabrication process for specialized applications, such as single-frequency laser systems.
Additionally, this study evaluated the properties of in-house inscribed large-diameter FBGs for temperature sensing applications. The fabricated FBGs exhibited promising performance, achieving a temperature measurement accuracy of $\sigma_{T'} = 0.55 ^{\circ}$C, closely matching the $0.55^{\circ}$C, the accuracy of a commercial FBG. This similarity in accuracy indicates that the in-house fabricated FBGs can perform at a level comparable to commercially available sensors.
Overall, this work successfully optimized a systematic and reliable FBG fabrication process, which has now been implemented at Modulight Corporation. Furthermore, the results highlight the potential of large-diameter FBGs for robust and precise sensing applications.