Laser drilling of micro holes of extraordinary quality and high aspect ratio is accomplished by laser-induced plasma erosion and requires a dedicated conditioning of the laser beam. In order to generate holes of high circularity and defined taper in metal sheets of up to 2 mm thickness, the beam needs to become conditioned using dedicated helical drilling optics. Within this drilling head, the beam profile is optimized such that the laser beam is rotating in itself and impingement angle as well as diameter of rotation trajectory onto the work piece can be fully controlled.