ABSTRACT
In direct-liquid-cooled thin-disk lasers, the laser passes through the coolant several times during the oscillation process. The temperature distribution of the coolant has a great influence on the laser wavefront. Comparison of the thermal-gradient-induced aberration of liquid has been conducted using D2O and CCl4 as coolants. The influence of the thermal conductivity and specific heat capacity of the coolant on the laser wavefront is analyzed too. The results show that liquids with poor thermal properties and high thermo-optic coefficients such as CCl4 cause serious wavefront aberration.
