A focused laser beam having an optical axis passes sequentially through a simple, positive lens, a pair of plane, parallel windows, and a second, simple, negative lens. Each of the plane, parallel windows are mounted to a galvanometer motor and positioned orthogonally to one another. The focused laser beam is therefore displaced in a controlled manner from the optical axis to enable laser machining of very precise geometric features over a large processing window. A field size of one thousand microns is achieved.