Fiber Bragg grating based displacement sensors: state of the art and trends

Abstract

Purpose The purpose of this paper is to present the latest sensing structure designs and principles of information detection of fiber Bragg grating (FBG) displacement sensors. Research advance and the future work in this field have been described, with the background that displacement and deformation measurements are universal and crucial for structural health monitoring. Design/methodology/approach This paper analyzes and summarizes the existing FBG displacement sensing technologies from two aspects principle of information detection (wavelength detection, spectral bandwidth detection, light intensity detection, among others) and principle of the sensing elastomer structure design (cantilever beam type, spring type, elastic ring type and other composite structures). Findings The current research on developing FBG displacement sensors is mainly focused on the sensing method, the construction and design of the elastic structure and the design of new information detection method. The authors hypothesize that the following research trends will be strengthened in future: temperature compensation technology for FBG displacement sensors based on wavelength detection; a study of more diverse elastic structures; and fiber gratings manufactured with special fibers will greatly improve the performance of sensors. Originality/value The latest sensing structure designs and principles of information detection of FBG displacement sensors have been proposed, which could provide important reference for research group.

Compliant Mechanism-Based Sensor for Large Strain Measurements Employing Fiber Optics

“…Fiber optic-based sensors are becoming very popular in a wide variety of applications, including measurement of strain, vibration, temperature, humidity, magnetic fields, and others [ 8 , 9 , 10 , 11 ]. In particular, fiber Bragg grating (FBG) sensors have become one of the primary fiber optic measurement technologies [ 12 , 13 , 14 , 15 , 16 , 17 ]. Their growing popularity is due to several advantages that they possess over traditional sensing technologies: (i) they do not require electrical power, (ii) optical fiber serves as the sensing medium and the signal transmission line, (iii) immunity to electromagnetic interference and ground loops, (iv) capability of being multiplexed and deployed over very long distances, (v) high sensitivity and resolution.…”

Sensitivity-enhanced all-fiber displacement sensor based on Lyot filter

“…Compared with traditional electronic displacement sensors, all-fiber sensors have attracted widespread attention due to their high resolution, small size, and low cost. In recent years, various types of fiber optic sensors have been used for displacement measurement, such as fiber Bragg grating(FBG) [1], long period grating(LPG) [2,3], Mach-Zehnder interference(MZI) [4] and bending interference [5]. Although these structures can measure displacement in the micrometer range, the manufacturing process is complex and only suitable for specific situations, and their precision still needs to improve.…”

Magnetic suction compression-type gap sensor based on fiber Bragg grating sensing

“…Many researchers have examined FBG displacement sensors. To measure the displacement, it is necessary to transform the displacement into the change in the stress acting on the FBG using a certain elastic convertor (Liu et al , 2019). Researchers often use a cantilever to design FBG displacement sensors (Baiou et al , 1999; Dong et al , 2001; Zhong et al , 2011).…”