Influence of the rake angle on the surface formation during micro shaping of submicron optical structures in Au-layers

The manufacturing of discontinuous micro-optical structures in the submicron range by shaping processes places high demands on the accuracy and reproducibility. With diffractive optical elements (DOE), the requirements can be in the nanometre range. Lithographic and mechanical procedures compete to achieve these requirements with a high variety of shapes. The mechanical production by ultra-precision machining (UPM) allows higher degrees of freedom and the manufacturing of optics with a higher efficiency. By comparison, lithographic processes ensure a reproducible accuracy. To eliminate this disadvantage, a further development of machine technology and process technology is necessary. For the mechanical production of planar diffractive optical structures, galvanic gold is an established material. In order to achieve the same results in structuring free-form surfaces on 5- Axis machines, the machine kinematics and the tool guide have to be reconsidered.