The influence of window thermal conductivity on the temperature distribution of the ADP crystal with large aperture

Motivated by the need of achieving the high frequency conversion efficiency of the laser beam with large diameter in the non-critical phase matching, a temperature control scheme of ADP crystal with large aperture was proposed. In this paper, in order to obtain the influence of the window thermal conductivity on the temperature distribution of ADP crystal, four different window materials, the thermal conductivities of which are different orders of magnitude, were proposed and analyzed by using the finite volume method (FVM) and experiments. The temperature distributions and temperature gradients of ADP crystal in the temperature control scheme with different window materials were discussed, and the optimal fourth harmonic generation (FHG) conversion efficiencies were obtained in different optics regions. Finally, the requirement of the window material thermal conductivity was proposed in order to obtain the high frequency conversion efficiency.