Accelerometer prototype based on enhanced fiber Bragg grating overlapping interrogation method

This paper presents the development and analysis of an optical biaxial accelerometer based on fiber Bragg gratings (FBGs) using an enhanced ratiometric interrogation method: Bragg grating overlapping interrogation. Typically, this method requires two FBGs for each sensing axis in the accelerometer. However, the configuration employed in this study comprises only one grating for each sensing axis and one reference FBG that demodulates the Bragg wavelength changes of both sensing FBGs, in addition to performing temperature compensation. This modified scheme enables the use of fewer gratings without requiring an interrogator, a device often unsuitable for in-field applications. This prototype is also temperature-insensitive, with a usable acceleration range of 0.1–1.0 g (1 g = 9.8 m/s2) for measuring the acceleration amplitudes of objects moving at frequencies of 0.1–20 Hz. These findings show that the developed prototype 2D accelerometer is suitable for real-world seismic applications.