Thermal effect of high power CO_2 laser's coupler window with reflecting coating

To solve thermal effect problem of the coupler window with HR coating of CO-2 laser caused by higher power oscillating laser in resonator,the temperature field and thermal deformation field of the coupler window were researched. Through analyzing the work state of resonant cavity,the mathematical expression of the oscillating laser in cavity with a blending mode was first given.The general solutions of temperature field and thermal deformation field of coupler window with the blending oscillating laser were obtained by the semi-analytic thermal analysis method.And the results were compared with the thermal solutions of the coupler window by the oscillating laser with the homogeneous distribution and the Gauss distribution.The results show that when the power of the oscillating laser in cavity is 3800W,the maximum thermal deformation of coupler window with the blending oscillating laser is 0.91μm,while the maximum thermal deformation by the assumptions of the homogeneous distribution and the Gauss distribution are smaller by 20.88% and larger by 78.02%.