Fast marking by solid state laser : development of a laser source optimized to the highest process productivity

Abstract: In the past decades, the laser technology market for industrial material processing has grown by double digits. Nowadays, material processing by high power laser represents the almost irreplaceable solution for many needs. The company SEI S.p.A., based in Curno, Italy, requested a solid-state laser suitable for fast marking application. A Nd:YVO4 crystal in end-pumped configuration was chosen in order to guarantee high performances, high quality and low cost. A study of the resonating cavity was made and thermal lensing was taken into account. The original solution here adopted, i.e., a low-doped (0.2 at. %) and relatively long (10 mm) crystal, allowed to reduce damaging thermal effects and to reach up to 17 W power in CW operation. Finally, a laser with quality factor M2 = 1.8 and peak powers of 9 kW at 50 kHz in Q-switched regime was realized. This first prototype was then improved and today commercialized under the name “Laser3”. More than 200 units have been sold so far.