Direct measurement of light-to-heat energy conversion during pure copper welding using a blue laser

Blue diode laser exhibits high light absorption rate in copper, which makes it advantageous for welding pure copper. Although it is well known that the optical absorption of metals varies with temperature and phase transitions, direct and quantitative measurements of absorption during laser welding remain limited. Therefore, the purpose in this study is to develop a calorimetric method for quantitatively measuring the energy absorption efficiency of pure copper under blue diode laser irradiation. This calorimetric method enabled a quantitative assessment of the energy absorption efficiency of pure copper when irradiated with the blue diode laser.