A contact inspection system for aspheric optical components

•Level principle is employed so that low contact force is possible (0.7mN).•The inspection and calibration models are carefully investigated and the reliability of the system is validated.•High precision (∼0.5μm) and fast scanning speed (2mm/s) are obtained with this system.•Our system could assist to improve fabrication efficiency and lower the costs. We construct a contact inspection system and realize low contact force and high precision measurements for aspheric optical components. The inspection and calibration principles, as well as the reliability of the system are thoroughly studied. Our investigations show that the system could provide low contact force measurement (low than 0.7mN), fast scanning speed (2mm/s), and high accuracy (as low as 0.5μm), being a good option to the contact inspections of aspheric optical components.