Hybrid tool combining stiff and elastic grinding

The fabrication process chain for optically smooth surfaces tends to include several time-consuming grinding and polishing steps. To reduce process time, a hybrid tool is proposed in which a stiff grinding tool and a shape adaptive grinding (SAG) tool are fused together, by taking advantage of the elastic nature of SAG tools. The material removal achieved by the hybrid tool is equivalent to discretely using the stiff grinding and SAG tools in sequence. Under similar processing conditions, a smooth surface of ∼0.02 μm Ra can be obtained on BK7 glass with the proposed tool, instead of ∼0.2 μm Ra with the stiff grinding tool.