镀铝衍射光栅表面有机污染物的等离子体清洗技术*

高能量激光装置中衍射光栅吸附的有机污染物是导致衍射光栅损伤的关键因素之一，采用等离子体清洗技术可以实现衍射光栅表面污染物的在线去除。通过有限元方法分析等离子体清洗范围，获得等离子体清洗半径随着清洗距离下降而增加的规律。研究等离子体清洗工艺参数与表面有机污染物去除效果间关系，结果表明随着清洗距离以及工艺气体中氧气含量的上升，镀铝衍射光栅表面自由能的极性部分和色散部分都会增加，其中极性部分的增加起主导作用。等离子体清洗后的镀铝衍射光栅表面呈现洁净状态的周期性锯齿形结构，并且 C1s(285.0 eV)峰值由 6.65×10⁴ 降低至 2.86×10⁴ 。研究等离子体清洗镀铝衍射光栅后表面自由能变化情况，结果表明镀铝衍射光栅表面的极性基团会吸附空气中的碳氢化合物，出现表面自由能下降的陈化现象。研究结果可为镀铝衍射光栅表面有机物污染物的等离子体在线去除提供新的途径。

Plasma Cleaning Technology of Organic Pollutants on Aluminized Diffraction Grating Surface

Organic contaminants adsorbed by diffraction gratings in high-energy laser devices devices are one of the key factors leading to diffraction grating damage. Plasma cleaning technology can achieve online removal of diffraction grating surface pollutants. The plasma cleaning range is analyzed by the finite element method, and the law that the plasma cleaning radius increased with the decrease of the cleaning distance is obtained. The relationship between the plasma cleaning process parameters and the removal effect of surface organic pollutants is studied. The results show that with the increase of the cleaning distance and the oxygen content in the process gas, the polar part and the dispersion part of the surface free energy of the aluminized diffraction grating increases. The increase of the polar part plays a leading role. The surface of the aluminized diffraction grating after plasma cleaning exhibits a clean periodic sawtooth structure, and the C1s (285.0 eV) peak decreases from 6.65×10⁴ to 2.86×10⁴ . The changes of surface free energy after plasma cleaning of aluminized diffraction gratings are studied, and the results show that the polar groups on the surface of aluminized diffraction gratings will adsorb hydrocarbons in the air, resulting in the aging phenomenon of decreased surface free energy. The research results provide a new approach for the on-line plasma removal of organic contaminants on the surface of aluminized diffraction gratings.