Large-range and high-sensitivity fiber optic temperature sensor based on Fabry-Perot interferometer combined with FBG

A compact fiber optic temperature sensor based on the Fabry-Pe & PRIME;rot interferometer (FPI) combined with FBG is analyzed and demonstrated experimentally in this paper. The FPI is fabricated by splicing a single mode fiber (SMF) with a section of silicon tube filled with ultraviolet (UV) glue to form an air microcavity. Owing to the high thermo-expansion coefficient of UV glue, the sensor can achieve a high sensitivity. Besides, the cascaded FBG can be used to locate different temperature intervals, and therefore the detectable temperature range is largely extended. Experimental results indicate that the sensor has a temperature sensitivity of-4.665 nm/? in a wide temperature range of-30 to 15 ?. In addition, our fiber temperature sensor also exhibited excellent consistency, good repeatability, and stability during the thermal cycle tests. Therefore, it has a good practical prospect.

Automated summary

This paper analyzes and experimentally demonstrates a compact fiber optic temperature sensor based on the combination of FPI and FBG. The sensor achieves high sensitivity by utilizing the thermal expansion coefficient of UV glue. Additionally, the cascaded FBG extends the detectable temperature range. The experimental results show that the sensor has a high temperature sensitivity in the range of -30 to 15 ℃. Furthermore, the sensor exhibits good consistency, repeatability, and stability during thermal cycle tests, indicating promising practical prospects.