A novel method for figuring and polishing diamond surfaces is described. It is a three step process, consisting of 1) a diffusion smoothing step using carbon reaction with certain materials at elevated temperatures, 2) a laser polishing and figuring step where UV laser ablation actively coupled with in situ interferometry provides the desired surface finish. The fist step of the process uses carbon diffusion into a hot iron surface to achieve an initial, relatively smooth surface of the as grown chemical vapor deposited (CVD) diamond surface. The technique can be used on any size CVD diamond and may be applied to curved surfaces. The second step, excimer laser ablation, is the backbone of the proposed method. By using an in situ, interferometric surface measuring and monitoring capability, diamond material may be removed from the surface in an accurately controlled manner, both in depth and width. The method is conceptually similar to single point diamond turning for figuring the optical surfaces of metal mirrors. The last step uses the properties of ion beam technology to change the top layer of the diamond surface into a soft and easily polishable amorphous carbon. The final surface finish of the accurately figured surface is obtained by conventional, high quality polishing techniques.
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