Research On Drive And Control Circuits Of Semiconductor Lasers In RFA And OTDR

Raman Fiber Amplifier(RFA)and Optical Time Domain Reflectometer(OTDR)are very important in the field of Optical communication technology.The performance requirements of semiconductor laser driver circuits in RFA and OTDR are constantly improving.In this paper,the RFA pump module and the semiconductor pulse laser driver circuit in OTDR are designed,and the corresponding simulation analysis and actual circuit test are carried out.The main research contents and relevant achievements are as follows:(1)The background and significance of this topic are introduced,the main development course of semiconductor lasers is briefly described,and the development and research status of lasers are summarized.(2)The working principle of semiconductor laser,the theoretical basis of RFA and the basic principle of OTDR are described.(3)System structure design of RFA pump module;Semiconductor pulse laser drive circuit design,mainly on the pulse trigger signal generation module,laser drive module,laser temperature control module design and implementation.(4)Zynq system architecture construction and schematic Design.The primary pulse generation module was designed through Verilog HDL language,and the IP core encapsulation of the functional modules was realized.In Block Design,the system architecture was built by calling various IP cores,and the relevant code was written by SDK development environment.(5)The performance test of the RFA pump module and the analysis of experimental data show that the maximum absolute error of the driving current is about 15 m A and the stability is up to 2.3%;When the pump module is turned on,the working temperature of the laser tends to be stable within 60 s.(6)Functional simulation of Zynq primary pulse generation module and test and analysis of actual circuit waveforms were carried out.The results show that the designed module can generate a variety of primary pulses with two-channel phase offset of 10 ns,20ns,50 ns,100ns,500 ns,1us,10 us,20us.And the pulse period can be adjusted according to the size of the measured distance,the corresponding output pulse period is 500 Hz,1k Hz,2k Hz,10 k Hz,20 k Hz,50 k Hz.It can be seen from waveform analysis that the rise and fall time of pulse is 2-3ns.(7)The performance test of the semiconductor pulse laser driving circuit shows that the electric pulse driven by the laser can achieve eight different pulse widths of 10 ns,20ns,50 ns,100ns,500 ns,1us,10 us and 20 us,which meet the design requirements.