FPGA Software Design Of Optical Fiber Brillouin Sensor Acquisition And Control

Distributed optical fiber sensors are widely used in pipeline detection,national defense security,and geological exploration under their small size,lightweight,and long-distance.Compared with distributed optical fiber sensors based on Rayleigh scattering and Raman scattering,the optical fiber Brillouin sensor can measure the environmental temperature and strain information at a longer distance.Based on the theory of Brillouin optical time-domain analysis,a fiber-optic Brillouin sensor acquisition and control system based on FPGA is designed and implemented in this paper.Under the flexibility,parallelism,and integration of FPGA,the device of the fiber optic Brillouin sensor is controlled and the sensing data is collected and processed.The research focus of this paper is the real-time sampling and accumulative averaging of high speed and large capacity data,the fast processing of large-capacity data,and the interaction of large-capacity data with external memory.Controller using the SPI protocol to receive the upper machine transmission optical fiber Brillouin sensor control signal parameters,according to the parameters to generate the synchronous sequence control,to realize the laser,semiconductor optical amplifier and AD converter device of synchronous control,and the optical fiber Brillouin sensor collected continuous analog signal into digital signal,through Fourier transform and inverse transform achieves rapid cross-correlation algorithm of sampling,signal processing,the massive digital logic with FPGA and DSP resources in FPGA to realize the long-distance real-time frequency shift estimation BOTDA system.