Influence of Technological Parameters on the Contrast of Copper Surfaces in the Laser Marking Process

This study investigates the influence of key technological parameters—including marking speed, raster step (Δx), pulse duration, power density, and effective energy—on the laser marking of copper samples using Yb-doped fiber and CuBr MOPA lasers. The experiments were conducted in two groups: the first used pulse durations of 100 ns and 200 ns with the fiber laser, and the second employed 30 ns pulses with the copper bromide laser. The marking speed was varied from 10 mm/s to 80 mm/s. The raster step Δx ranged from 3 µm to 20 µm for the fiber laser and from 3 µm to 27 µm for the CuBr laser. The results are compared across different pulse durations of the fiber laser, and the influence of the laser wavelengths on the marking process is examined. Optimal ranges of effective energy for raster marking were identified: for the Yb-doped fiber laser, the range is 17.4 – 43.1 kJ/cm², and for the CuBr laser, 9.90 – 43.1 kJ/cm².