LASER PROCESSING APPARATUS WITH MIRROR HAVING DIFFERENT CONCAVE PROFILES

摘要

The laser processing apparatus including a concave mirror (2.2) which directs a radiation beam (5) reflected by the surface of a workpiece (4) back onto the said workpiece (4) is characterized in that the concave surface (6) of the mirror (2.2) is a combination of different concave profiles (6, 6.2),preferably a sphere (6) and an ellipsoid (6.2). Favourable results are also obtained by applying a mirror (2.2) with a surface formed by combining the profiles (6, 6.2) of a paraboloid and/or an ellipsoid and/ or a sphere. The shape of the mirror (2.2) is intended to help increase the efficiency of the laser-workpiece system and generate a secondary beam (5"), which is responsible for the formation of an absortive layer. The amount of the secondary radiation beam (5") can be regulated depending on the type of material to be treated.