The Design Of A Laser Drive Current Source And The Study Of Frequency Point Current Acquisition Method

With the development of science and technology,the semiconductor laser ranging system with better monochromatic,more directional and longer range has become the current demand of science and technology development.The range accuracy of semiconductor laser depends on the performance of the laser device,much depends on its driving current ideal and temperature stability.According to the requirements of China rocket technology institute 102 project,This paper needs to design the S7500 semiconductor laser multi-channel drive current source with small size,high precision,low temperature drift,fast response,low noise and preset of output waveform features.This paper proposes the design idea of S7500 semiconductor laser driver current source and realized the physical design.To further improve the range accuracy,this paper studies the acquisition and fitting method of frequency point current.The main research work is as follows:First,according to S7500 semiconductor laser range principle,application and technical indexes make it overall design.The entire driving current source system includes the V/I transform unit and the waveform generator circuit unit.The circuit structure design and device selection simplifies the circuit structure,improved circuit integration and reliability,and reduced the temperature drift of the circuit.Second,this paper describes the waveform data occurrence method and control circuit design based on FPGA technology.Using FPGA technology to make the driving current source has arbitrary waveform preset capability,The output waveform has three modes: single point,single waveform and infinite waveform.According to the above scheme,carries out the physical design.Carried out the experimental results and error analysis.Third,this paper studies the method of frequency point current acquisition is and designs the data acquisition circuit.Fitting the point frequency current data obtained by binary method,by increasing the linearity of the driving current to improve the linearity of the frequency modulation curve of the semiconductor laser,Furthermore,improves the range accuracy of semiconductor laser.