Design Of Receiver For Distributed Brillouin Fiber Optic Sensing System

Optical signal receiver is an important part of distributed Brillouin fiber optic sensing system.Its performance determines the performance of the whole fiber optic sensing system.The sensitivity of receiver has an important influence on the performance of the sensing system.In this paper,the distributed Brillouin fiber sensing system and its overall design scheme are introduced.According to the system requirements,the optical receiver schematic diagram and PCB are designed.Under the guidance of theory,each function module is reasonably planned,and the selection of key devices and the calculation of circuit parameters are deeply analyzed.The paper analyzes and demonstrates the power supply module,temperature control module,high voltage amplifier module and control module in detail.The power module provides stable and low noise power supply for each function module.The temperature control module monitors and controls the temperature of the fiber grating and the avalanche photodiode(APD)to make them work in the best performance state.The high-voltage amplifier module attenuates the noise and amplifies the weak signal after photoelectric conversion.The three-stage amplifier circuit is designed to suppress the self-excited noise caused by high gain.The control module includes the microcontroller and its peripheral circuit,which communicates with each functional block to serve the receiver cooperatively and efficiently.The paper carries on the experiment test to the final printed circuit board,the test result is in line with the expected design,realizes the effect that each function module needs.