LASER BEAM MACHINING DEVICE AND LASER IRRADIATION METHOD

摘要

PROBLEM TO BE SOLVED: To obtain plural converging (machining) spots of nearly same size on a workpiece, when plural places of the workpiece are simultaneously machined by branching one laser beam, even in laser machining by using ultra-short pulsed laser such as a femto-second pulse. SOLUTION: A laser beam machining device for simultaneously machining plural places of a workpiece with a laser beam is equipped with a phase grating 2 which produces plural diffracted beams by branching a laser beam 1 and with a converging optical system 8 which consists of a lens 6 for converging the plural diffracted beams on the plural places of the workpiece 4 and a diffraction element 7 for making compensation for chromatic aberration.