Despite its high reflectivity and thermal conductivity, aluminum less than 6 mm thick can be cut, depending on the alloy type and laser capability. When cutting with oxygen, the cutting surface is rough and hard. When nitrogen is used, the cutting surface is smooth. Pure aluminum is very difficult to cut because of its high purity. Only when the "reflection absorption" device is installed on the system can the aluminum material be cut. Otherwise, the reflection will destroy the optical components.