1. Generally, the smaller the resistivity of a material, the lower its absorption rate of laser. The figure below shows the resistivity ranking of different materials at 20°C. By comparison, we can find that the resistivity of silver and copper is very small, that is, their high reflection ability is very strong.
2、Different materials have different absorption rates for different wavelengths of light.
As shown in the figure below, copper (Cu) and silver (Ag) are highly reflective materials for fiber lasers with a wavelength of 1070nm, and their absorption rates are very low, much lower than iron (Fe) and steel (Steel); however, their absorption rates for solid lasers are relatively much higher.
ok now how to cut high reflective material ，for example copper；
(1) When cutting brass, copper and other materials, be conservative in speed, leave some space, and don't be too extreme.
(2) Copper must be cut with oxygen, not nitrogen or air.
