Optical machining of a workpiece with coherent light scanning a plate with a plurality of subaperture subapertures is disclosed. Each of the subapertures creates a working image which when scanned with a coherent wave front of the design frequency forms in three dimensional space the working image. The...http://www.google.de/patents/US5633735?utm_source=gb-gplus-sharePatent US5633735 - Use of fresnel zone plates for material processing
