Damage-free high-planarity monocrystalline silicon carbide planar optical element and preparation method thereof

The invention discloses a damage-free high-planarity monocrystalline silicon carbide planar optical element and a preparation method thereof. The preparation method comprises the following steps: (1)selecting a whole single crystal silicon carbide crystal ingot with a zero micro-pipeline; (2) cutting the single crystal silicon carbide crystal ingot to obtain a rough blank; (3) carrying out double-sided grinding on the rough blank to obtain two parallel rough grinding surfaces; (4) polishing the two parallel rough grinding surfaces to obtain an optical mirror surface; and (5) carrying out chemical mechanical polishing on the optical mirror surface, removing a damaged layer of the mirror surface, and carrying out local finishing to obtain the damage-free high-planarity monocrystalline silicon carbide planar optical element. 本发明公开一种无损伤、高平面度单晶碳化硅平面光学元件及其制备方法。所述制备方法包括以下步骤：（1）挑选零微管道的整块单晶碳化硅晶锭；（2）对该单晶碳化硅晶锭进行切割，得到粗坯；（3）对粗坯进行双面研磨，得到两个平行的粗磨面；（4）对两个平行的粗磨面进行抛光，得到光学镜面；（5）对光学镜面进行化学机械抛光，去除镜面的损伤层，并进行局部修整，得到无损伤、高平面度单晶碳化硅平面光学元