Diamond Machining of Holograms Using Fine Rectangular Shaped Cutting Tools

Diamond machining is a flexible process ensuring an excellent workpiece precision. In combination with fast tool servos, which dynamically modulate the depth of cut, diffractive microstructures and holograms can be machined. The complexity and functionality of the structure depends on the flexibility of the machining process. Novel diamond tool geometries with fine rectangular shaped cutting edges and a width below 20 μm extend the machinable structure geometries. This paper presents fundamental cutting experiments using these novel tools with widths of the cutting edge of 10 μm and 20 μm to machine diffractive microstructures with a rectangular shaped profile. Particularly, the influence of the feed on the uniformity of the structure width and on burr formation on the structure edges is investigated. Using these tools together with fast tool servo assisted diamond turning holograms for multiple wavelengths can be machined, forming different intensity patterns in dependence of the wavelength.