Research On Circuit Of Raman Fiber Amplifier And Optical Time Domain Reflectometer Optical Signal Detection And Processing

Optical signal receiving is an important part of optical fiber communication system.The performance of the receiver determines the communication quality.Therefore,this paper will study the circuit of the optical signal receiving module of Raman Fiber Amplifier and Optical Time Domain Reflectometer based on low noise and low interference Angle.RFA uses a pumped laser to amplify the signal light in the fiber,and the multichannel pumped laser amplifies the multi-wavelength composite light transmitted in the fiber simultaneously.However,there is a phenomenon that RFA has different gain for different wavelengths.Therefore,in order to smplificate optical signals in each channel on average,it is necessary to detect the power of optical signals in each channel to get the gain flatness between different channels.OTDR is an instrument used to measure the performance of optical fiber.By using OTDR,the distribution of optical fiber characteristics along the distance as well as the information of optical fiber attenuation,connector loss and the fault of optical fiber can be obtain.The main research contents and results of this paper are as follows:(1)The background and development of RFA and OTDR are briefly introduced.(2)The primary principle of RFA,the components of RFA detection system,the basic principle and related parameters of OTDR,the working principle of cross-resistance amplifier,the circuit noise analysis,the design theory of low-pass filter circuit and power are introduced.(3)The design of each circuit and software flow of the RFA detection system are introduced.Focus on the buck,photoelectric conversion,gain regulation and other circuits,Lab VIEW upper computer and peak power detection,gain regulation detection algorithm design;(4)The design of each circuit and software flow of the OTDR detection module are introduced.Focuses on the design of boost,photoelectric conversion,high-speed ADC and other circuits,and completes the design of high-speed equivalent sampling algorithm based on FPGA(5)The test results show that the RFA multi-wavelength detection system can detect the peak power in the power range of 7.02 d Bm at fixed gain.After the gain regulation circuit is added,the detection range is expanded to 14.66 d Bm,and the minimum detection optical power is 3.31 n W.The maximum error between the ratio of the peak voltage of each channel measured by the detection system and the ratio of the peak power of each channel measured by the spectrometer and the peak voltage of the first channel measured by the detection system is 0.1.The OTDR optical signal receiving module achieves a sampling rate of 100 MSPs with two ADCs with a sampling rate of 50MSPs.