Fiber-Optic Acceleration Sensor on Duplex Fiber Bragg Structures

Abstract

We propose an assessment of the possibility to use narrow-band fiber Bragg structures as the basis of a measuring system for an acceleration sensor (accelerometer). The assessment of applicability is carried out on the basis of mathematical and computer simulation and analytical assessments of the model's working capacity. We propose to solve the problem by transferring a signal from the optical (THz) to the radio frequency (GHz) range of measurements due to the theory and technology of radiophoton methods. The result is a significant increase in the signal-to-noise ratio. We suggest to use the measuring system based on two narrow-band fiber Bragg gratings with the following two properties: central frequencies are in the optical range, and a difference of central frequencies is in the radio frequency range of the spectrum. The optical signal obtained in the optoelectronic circuit is fed to a photodetector. An analysis of the resulting electrical signal allows to make a conclusion on the magnitude and direction of the force acting along the axis of the sensor sensitivity. The magnitude of the effective inertia force is directly related to the acceleration acting on the measuring system. We propose an approach to determine the magnitude of the effective force. The approach does not require measurement of the intermediate radio frequency, and determines the dependence of the effective force on the magnitude of the dual-frequency beats modulation factor. We propose to implement the design of the sensor in such a way as to minimize the effect of temperature deviations on the measuring system as a whole.