Study on the cooling method of deformable mirror under laser irradiation

Abstract

The deformable mirrors are becoming more and more important in laser systems. As the laser power increases, the deformation of the thin mirror also increases under laser irradiation. In this paper, to reduce the temperature rising, several cooling methods were proposed. These methods include air knife cooling, pole heads cooling, PZTs + pole heads cooling, Cu columns implanted around PZTs cooling, and PZTs inter-infill cooling. This paper mainly calculated the cooling effect of these cooling methods on the deformable mirrors under laser irradiation. In addition, the different cooling media such as water and air was also studied. Based on the results, we found the air cooling effect is poor, and water cooling effect is obvious. The cooling effect of adding heat-conducting sheets and Cu columns is not obvious. It has a good cooling effect when adding a heat-conducting Cu block with the same honeycomb shape as PZTs on the back of the mirror, and the temperature rising can be reduced from 7.46 °C to 2.96 °C. These calculations are valuable for the application of deformable mirror cooling.