Research On High Performance Semiconductor Laser Drive Technology

After decades of development of semiconductor technology,the maturity of the Laser Diode(LD)technology are higher,LD is lighter compared with other lasers,the volume is smaller than other laser,the process of modulation is very simple,these very obvious advantages of the semiconductor lasers in many fields have a very large effect,for example laser measurement,optical fiber communication,archaeological exploration,satellite communications,military and other important areas.The main effect that the running semiconductor laser maintains safe and stable,is from that current injection stability,temperature stability and laser operation by semiconductor laser external.So,this topic is to ensure semiconductor laser has a safe working condition for the purpose,according to the characteristics of semiconductor lasers and the driving requirements of semiconductor laser,the project design a high stability and high accuracy of the semiconductor laser drive way.The semiconductor laser driver technology is mainly composed of two parts,including semiconductor laser current drive circuit and intelligent temperature control circuit.The circuit of semiconductor laser current is driven by negative feedback control principle,through the attribute variable feedback is divided into two modes,respectively APC mode(Auto Power Control mode)and ACC mode(Auto Current Control mode),the two modes are steady constant control of the output optical power of semiconductor laser and drive current,the theoretical basis of this paper is based on the chip of TI 430 Series Microcontroller Unit(MCU)circuit and iC-HT as the main content of the design of semiconductor laser current drive part.Based on the theory of negative feedback control,the intelligent temperature control system is designed based on PID(Proportion Integration Differentiation),and the intelligent temperature control circuit is based on MAX1978.The TEC and the thermal resistance of semiconductor laser module collect the semiconductor laser's temperature,then the collected temperature value compare with the set of external theoretical value,the difference is the amount of feedback that drive TEC to control the laser temperature,the process makes the laser temperature stable.According to the security of LD,this paper also designs the PI circuit and RS485 communication circuit.Finally,the feasibility of the circuit is verified,and the design of the semiconductor laser driver circuit has achieved very good results.