Focusing elements for laser processing of materials

The paper examines the development of focusing elements which can produce in the focal plane an image consisting of a given set of points or line segments with an efficiency approaching 100 percent. A possible approach to the problem of marking articles and punching sets of holes is to use computer-synthesized plane focusing elements. Focusers for marking and for punching sets of holes in materials by means of CO2 laser beams have been fabricated. Amplitude masks of the focusers are shown, with particular attention given to the focusing of light into a cross by an element operating at an incidence angle of 45 deg.