High-temperature sensor based on SCSCS optics fiber structure

In this paper, a high-temperature optical fiber structure sensor based on Mach-Zehnder interference has been proposed and experimentally validated. The sensor is constructed via the fusion-splicing of a segment of coreless fiber (CLF) with a piece of seven-core fiber (SCF), followed by fusion-splicing another section of coreless fiber that links two single-mode fiber (SMF) structures. This configuration provides a single-mode fiber/coreless fiber/seven-core fiber/coreless fiber/single-mode fiber (SCSCS) optical fiber structure. The high-temperature characteristics of this sensor have been examined via an experiment. The results indicate that the length of the seven-core optical fiber has a minimal impact on the sensitivity spectrum to temperature. It is also shown that the sensor demonstrates excellent repeatability and stability. The sensor can withstand temperatures up to 1000 °C, and has a sensitivity of 0.026 nm/°C. The standard deviation of stability is 0.167, while the sensor exhibits good periodicity. This proposed sensor has significant potential for applications in high-temperature environments such as aviation, aerospace, and mineral mining.