The results show that thermal compensation in non-irradiant areas could reduce the temperature gradient of mirror for high-power laser, and then could decrease the thermal deformation significantly.
Of the existing phase compensation methods, the phase gradient autofocus (PGA) algorithm is a better one.
在现有的相位补偿方法中，相位梯度自聚焦（PGA）算法是较好的一种。
3
The control strategy for surface temperature of the core rod is investigated and the scheme of introducing advanced compensation on the quantity of inlet water by gradient function is stated.