High-sensitivity temperature optical sensor based on long-period fiber grating

摘要

We propose a high-sensitivity temperature sensor with a long-period fiber grating (LPFG) using Mach-Zehnder and Sagnac interference of the optical path. The LPFG sensor achieved a good repeatability and stability of temperature response with a sensitivity of 0.083nm/℃ in the range of 40℃-120℃. Comparing to the traditional fiber Bragg grating (FBG) sensor, the LPFG sensor shows 10 times higher temperature sensitivity than that of the FBG, so the problem of low sensitivity of FBG is solved. Otherwise, Mach-Zehnder and Sagnac interference of the optical path have the advantage of simple structure and good practicability which can replace the complex optical path in the special environment.