The Research On The Control Systems Of MOPA Pulsed Fiber Lasers

With the development of science and technology,laser processing has become increasingly important in the processing and manufacturing industry.In the laser processing industry,pulsed fiber lasers play a decisive role.Among them,the pulsed fiber laser with a MOPA(Master Oscillator Power Amplifier)structure has its unique advantages.This paper investigates the development,studies and designs the control systems and drive circuits for pulsed fiber lasers with MOPA structures.Mainly include the following:1)The laser machine circuit structure and system control program.2)Seed source fast drive circuit and pulse shape control system.3)Pump source high current drive circuit,red laser drive circuit and its program control module.Including the constant current source drive circuit,DC-DC power supply design and constant current source program control program.4)Abnormal detection alarm circuit and system control scheme.Including PD(photodiode)detection circuit,temperature control and NTC(negative temperature coefficient)thermistor detection circuit and supply voltage detection circuit.5)Communication interface circuit,communication protocol and communication control scheme with the host computer.6)Summarize the mistakes and deficiencies in the design process and analyze how to conduct further research.Among them,the circuit part uses the circuit design software to carry on the schematic diagram and the PCB design;The control system uses the hardware programming language VHDL to write,the control program disposes on two pieces of CPLD(Complex Programmable Logic Device)chip,Control the working status of the circuit.Finally,the laser can work stably with an average output power of more than 20 W,a pulse width as low as 1 ns,and a repetition rate of 1 kHz to 2 MHz continuously adjustable at a wavelength of 1064 nm.Among them,power,frequency,pulse width and other parameters can be flexibly controlled to facilitate the user's operation.In addition,the laser self-protection function has been added,further increasing the stability of the system.