Study on Diamond Cutting of Nonrationally Symmetric Microstructured Surfaces with Fast Tool Servo

The nonrationally symmetric microstructured surfaces (NRSMS) were used widely in complicated optical systems as their almost arbitrary surface shapes allow to carry out the complex phase transformations. The diamond cutting based on fast tool servo (FTS) was one of practical technologies for machining complex optical elements with a nanoscale surface roughness and submicron profile accuracy. In the present paper, the geometric parameters design principles of diamond tools for cutting of C2 continuous NRSMS with FTS were analyzed in detail. A diamond tool for machining sinusoidal grid microstructured surfaces was designed and fabricated successfully based on the design principles. An arc-equal strategy for tool path control points generation was proposed. The feasibility of the diamond tool design and of the arc-equal path generation scheme were experimentally verified by a series of diamond cutting tests of sinusoidal gird microstructured surfaces with FTS. In addition, the magnitude and the direction of machined surfaces deviation caused by the tool center alignment error were also discussed in the article.