Anti-vibration surface reconstruction method for on-machine coherence scanning interferometric measurement

Single-point diamond cutting technology is extensively used for machining high-precision optical surfaces with microstructures. Coherence scanning interferometry (CSI), offers high measurement efficiency and can achieve sub-nanometer noise levels. Integrating CSI system in a diamond cutting machine may allow on-machine surface measurement with an extended degree of freedom by utilizing the motion axes of the machine and avoid repositioning errors of the machined part after the off-line measurement. However, environmental vibrations inside the cutting machine may introduce measurement errors. In this study, we investigate the impact of vibration on the transfer function of CSI, and develop an anti-vibration surface reconstruction algorithm for on-machine CSI measurement. The influence of high-frequency vibrations is mitigated using a specially-designed filter, while the influence of low-frequency vibrations is addressed through inverse phase compensation. This method is validated experimentally with an ultra-precision single-point diamond turning machine.