Study of the drift and deformation for COIL output beam spot

Through the analysis and experiments on the far field beam spot drift and deform during the high-energy density chemical oxygen iodine laser operation, the conclusion that the alignment of the reflex mirrors in the resonator takes a very important roles is gotten. It is indicated that to improve the stability of the resonator box and the alignment of the reflex mirrors in the resonator before the laser operation is an effective method for decreasing the output far field beam spot drift and deformation.