Study On The Method Of Semiconductor Laser Two-level Coupling Temperature Control

The semiconductor laser has the advantages of high power light,detection distance,strong direction and small divergence angle.It can be used for space rendezvous and docking optical sensors,as a relative state measurement equipment cooperation and sign free round-trip spacecraft rendezvous and docking.In order to ensure accurate detection,need to work in the determination of semiconductor laser power and fixed non visible light,to avoid sun light interference,starlight stray light.However,a significant characteristic of a semiconductor laser is very sensitive to temperature changes,the wavelength,threshold current,power and life will be affected by changes in temperature,space in high and low temperature environment,semiconductor laser to long term affected by the solar radiation and the self heating,in order to ensure the success of the rendezvous and docking must take strict measures of temperature control of semiconductor laser.Based on an equivalent circuit model of thermoelectric refrigerator,two levels of coupling temperature control model is established,the model of the semiconductor laser components external environment as the first level temperature control object,through the first level temperature control,establish a relatively stable controlled environment,on this basis,then the components of the internal environment as the second temperature control object,so as to realize the control of high stability.By analyzing the internal structure and heat transfer characteristics of semiconductor laser components based on two-level coupling temperature control of the structure of the semiconductor laser constant temperature control algorithm,the algorithm combines switch refrigeration heating methods and the advantages of digital incremental PID control,effectively improve the temperature control and stabilityAccording to high and low temperature application background and requirements of the system reliability,this paper is based on the equivalent circuit model of thermoelectric cooler,established two stage coupling type temperature control model,the model of the semiconductor laser module of the external environment as the first stage temperature,the first temperature control,establish a controlled environment is relatively stable,on this basis,the components of the internal environment as the second stage temperature control object,in order to achieve high stability control.The simulation analysis of the key lies in the first stage temperature control cooling measures,the key lies in second temperature heat insulation measures.Design a set of two-level coupling temperature control method based on semiconductor laser temperature control system,the system can realize laser power step adjustment and temperature control,and tested on the hardware system.Analysis of experimental results,the temperature stability of 0.15?,the output stability of light power 0.17%,has the very good engineering practical value.