Numerical Simulation And Experimental Study Of Heat Stress Of RF-excited CO₂Laser Discharge Chamber

RF-excited CO₂laser has been widely used in the field of laser processing, However,there are some problems in the practical application of engineering, like instability of laserpower, only work a short time, which seriously affect the efficiency of the laser and anincrease in production costs. The discharge chamber of laser which stored laser gas playsan important role in the high stability of the laser output, compact and miniaturized laserdevices. The raise of gas temperature will lead to decrease in output power; thermal stressis generated because of nonuniform distribution of temperature, which can cause thedeformation of the discharge chamber. This article based on numerical simulation oftemperature and stress field of the laser discharge chamber, then does different experimentcompassion and determines the structure and assembly of discharge chamber, it isimportant and valuable of instability of laser power in practical laser. The main content isas follows:Firstly, it introduces the RF-excited CO₂laser research status and their advantages anddisadvantages. Then, it described the practical problems encountered in the practicalengineering process, the reason of focusing on the charge chamber，and influence of thetemperature factors and thermal stress on the laser discharge chamber.Secondly, temperature distribution and thermal deformation of the discharge chamberrunning is calculated and analyzed with the use of finite element simulation technology.We find out deformation of the internal electrodes of laser discharge chamber will begenerated due to oversize of assembly gap between the components inside the dischargechamber, the poor accuracy of assembly, nonstandard of assembly process, andnonuniform of the temperature distribution, which will affect the laser gas ionization andlead unnecessary power loss. To solve these problems we proposes to four modifiedassembly of the laser discharge chamber, then analyses temperature distribution andthermal deformation of four programs. It made a comparison of five numerical simulationresults, the scheme II was picked up to carry out final experiment. Thirdly, to test the performance of the scheme II discharge chamber, it took the fivedischarge chambers of scheme II and five discharge chambers of engineering whichassemble ten laser, let them operate continuously for five days in the same workingenvironment respectively, then record power every30minutes, finally we made thecontrast test, then analysed and contrasted experimental data, concluded: it is more stableand efficient assembled by the discharge chamber of the scheme II lasers.So far, the laser is running well by assembly of the scheme II.