A novel temperature self-compensation FBG vibration sensor

Abstract

There has been considerable interest recently in the development of fiber optic sensors based on Fiber Bragg gratings(FBGs)and FBGs are being used in various applications. In the measuring of the FBG, temperature compensation is one of the most important aspects. This paper describes a new FBG sensors use two FBGs and packaged them with novel structure, and then they can achieve self-compensating of temperature. Two FBGs with 0.2nm different wavelengths are made in one optic fiber, and they are fixed on symmetrical position of a cantilever girder's surface. Wavelength shift of two FBG caused by the temperature is equal and can be eliminated. To inspect and verify the FBG vibration sensor, we fixed it on the standard vibration system, and set the vibration frequency from 5Hz to 30Hz, record the wavelengths of two FBGs over time. The experimental value caught by this novel sensor and setting value is agreement. This sensor have a good frequency response characteristic, it can measure vibration frequency accurately.