A nanomeasuring machine based white light tilt scanning interferometer for large scale optical array structure measurement

White light vertical scanning interferometry (VSI) has been well developed during the past two decades and it is well suited for optical component evaluation due to its non-contact nature. However, because of its inherent limits in the field of view, the VSI is incapable of performing large range measurements. For large surfaces, stitching must be employed. In this paper, a nanomeasuring machine (NMM) based white light tilt scanning interferometer (TSI) is described, which can evaluate an optical array component in one round, without the need for stitching. By integrating a NMM, the tilt angle in the TSI no longer will require to be calibrated, easing in this way the realization of the TSI. With a tilt stage mounted on the NMM, the proposed system has two angles related to the measurement, which can provide excellent “fringes slipping out” correction ability. The analysis and the experiments are given.

► NMM is used to provide a precise scan angle without the need of calibration. ► The system has two angles configuration: tilt angle and scan angle. ► The system can easily adjust the measurable range and avoid “fringes slipping out”. ► “Data strip” is used as the minimum unit in data processing.