Figure 1

The morphology of the zirconia surface after surface machining by femtosecond laser with different processing speed, showing that with the decreasing of the processing speed, the depth of the machined grooves increase. (a) The schematic showing the surface machining process, and the morphology of the zirconia surface after femtosecond laser surface machining with a processing speed of (b) 1000 μm/s, (c) 600 μm/s, (d) 200 μm/s, (e) 100 μm/s, a sharp corner can be observed at the concave of the machined grooves.