Research On The Stress Analysis Of Vacuum Box And Resonator Stability For High Power CO₂ Laser

High power CO₂ laser is the most widely used laser in laser cutting, welding andsurface treatment for the industrial field nowadays. Among these lasers, high powertransverse flow CO₂ laser is a important light source in such processing applications. In thethesis, we focus on the deformation of the laser shell, which is generated by the insdie andoutside pressure difference when the laser is operating. The deformation that acting on theoptical bridge rod and the mirror bases on both ends of the optical bridge rod degrades theperformance of the lasers. In the thesis, systematically analysis of the effects of thedeformation has been made. The main research contents of this thesis are as follows:(1) The development status of high power CO₂ laser is introduced, and several majorfactors that affect the stability of high power CO₂ laser has been pointed out. Meanwhile, theapplications of high power CO₂ laser processing system has been presented briefly. And laserbeam with high beam quality and high power stability are the trend.(2) On the high power transverse flow CO₂ laser, the distance between the location ofthe point of the output light and the reflected light in the frame were measured to find out thethe deformation of the laser shell, which is generated by the insdie and outside pressuredifference. The deformation that acting on the optical bridge rod and the mirror seats on bothends of the optical bridge rod degrades the performance of the lasers.(3) When the pressure difference is changing, electricity measurement method is takento detect the stress distribution on the laser shell and the mirror bases of the resonator cavityexperimentally.(4) An ANSYS simulation analysis model, which consists of high power transverseflow CO₂ laser shell, optical bridge rod and mirror bases, are established. The effects on thestability of the resonator, which are caused by the inside and outside pressure difference onthe laser shell, are calculated and analyzed with the finite element method. Then, basing onthe calculation and analysis results, for optimizing the mechanical structure design of highpower transverse flow CO₂ laser vacuum case and the resonaor cavity, an effective andfeasible advice is got. According to the optimized design, a finite element analysis has beendone. The results show the stability of the resonaor cavity would be significantly improved. The research contents of the thesis has the theoretical and practical significance toimprove the operating stability of the high power transverse flow CO₂ laser and itsprocessing system.