highlighting that a deeper and wider cut can be made by using a higher laser power. From the figure, it can be noticed that an amount of material are not completely ejected but still remain inside the cut channel as shown in Fig. 5(c) and (d). This feature is more evident for a higher power condition, in which more molten material can be introduced but some of them were expelled. When a deeper cut is formed, the molten material requires a longer distance to vertically escape from the cut channel. With the limited recoil pressure, the kinetic energy of molten is not high enough to push itself away from the cut. Therefore, the liquid material likely solidified in the cut channel and became a recast layer as a consequence. However, the molten material can downwardly eject from the cut when a through channel was formed. This can result in dross on the backside of workpiece as shown in Fig. 5(d).