Direct driven inert confined fusion(D-D ICF)is a potential way to realize fusion with sub-MJ laser.And the Heaven-Ⅰhigh power excimer laser system,as an attractive driver for D-D ICF,has some unique advantages such as high homogeneity and beam zooming capability.The energy output of the MOPA system play a key role in Direct driven inert confined fusion (DD ICF) is a potential way to realize fusion with sub-MJ laser. And the Heaven-I high power excimer laser system, as an attractive driver for DD ICF, has some unique advantages such as high homogeneity and beam zooming capability. energy energy of the MOPA system play a key role in