“…Compared with traditional sensors based on electricity, optical fiber sensor has a series of advantages, such as light weight, high sensitivity, good resistance to electromagnetic interference, excellent electrical insulation and safety performance [1]. So far, optical fiber sensor has been widely used to monitor strain [2,3], temperature [4][5][6], refractive index [7], humidity [8], acceleration [9], ultrasound [10,11], displacement [12] and other physical quantities. According to whether occur light interferes or not, optical fiber sensors can be divided into interferometric optical fiber sensors and non-interferometric optical fiber sensors, of which interferometric optical fiber sensors normally have higher accuracy [13][14][15].…”