Abstract

Advances in flexible, precision aspheric form measurement using axially scanned interferometry Zygo’s Verifire™ Asphere (VFA) measuring instrument relies on translating the test part along the optical axis of a laser Fizeau interferometer while collecting interference fringes from areas of low slope relative to a spherical reference surface. The data are assembled into a final surface profile using the instrument geometry and scan history. Here we report on the latest advances for this system, including auto-alignment, measurability calculations, automatic focus tracking, distortion and magnification calibration, and a new job-centric user interface. We describe the new system, show measurement examples, and illustrate how the improvements improve the metrology and user experience.