Material Impact on Diamond Machining of Diffractive Optical Structures for UV-Application

This paper discusses the impact of different machining parameters on structuring quality in a diamond turning process for the machining of diffractive optical elements (DOEs). Special attention is paid to the impact of the material on the geometric structuring quality. First, the machining process for DOEs is described. The structuring process is based on a face turning process combined with a nano Fast Tool Servo (nFTS), which varies the depth of cuts within a range of up to 1 mu m at a maximum frequency of 5 kHz. The diamond tools being used exhibit customized rectangular tool geometry with a tool width of 10-20 mu m. To determine the material impact and the influence of several machining parameters, different structures have been machined, and their geometric and topographic quality has been analyzed.