Effective engraving requires a small laser spot and concentrated power, only with these two conditions can ensure the accuracy and depth of engraving. When the laser beam is just shot from the laser, the diameter is about 3 mm, the power density is low and cannot be engraved, after the focusing mirror is focused, the beam at the focal point is thin, the diameter is about 0.1 mm. Therefore, the plane to be engraved is fixed at the focus of the focusing mirror is a prerequisite for successful engraving.
1. Simple Focusing
2. Complex focusing