Metal-coated high-temperature strain optical fiber sensor based on cascaded air-bubble FPI-FBG structure

Metal coatings can protect the fragile optical fiber sensors and extend their life in harsh environments. However, simultaneous high-temperature strain sensing in a metal-coated optical fiber remains relatively unexplored. In this study, a nickel-coated fiber Bragg grating (FBG) cascaded with an air bubble cavity Fabry-Perot interferometer (FPI) fiber optic sensor was developed for simultaneous high temperature and strain sensing. The sensor was successfully tested at 545 degrees C for 0-1000 mu epsilon, and the characteristic matrix was used to decouple temperature and strain. The metal layer allows easy attachment to metal surfaces that operate at high temperatures, enabling sensor-object integration. As a result, the metal-coated cascaded optical fiber sensor has the potential to be used in real-world structural health monitoring.(c) 2023 Optica Publishing Group under the terms of the Optica Open Access Publishing Agreement

Automated summary

Metal coatings can protect optical fiber sensors and extend their lifespan in harsh environments. A nickel-coated fiber Bragg grating combined with an air bubble cavity Fabry-Perot interferometer fiber optic sensor was developed for simultaneous high-temperature and strain sensing. The sensor demonstrated successful testing at 545 degrees C for 0-1000 microstrain, and the characteristic matrix was used to separate temperature and strain. With its ability to attach to high-temperature metal surfaces, the metal-coated optical fiber sensor has potential applications in real-world structural health monitoring.