Phase difference interferometry system for wave front measurement for optical imaging system uses mask structure on object side and grating structure on image side

摘要

The phase difference interferometry system for optical imaging has an object pupil midway between an object-side positive lens and an imaging-side positive lens. It uses a black-and-white mask structure (6a) on the object side and a checkerboard grating structure (7a) on the image side. Various interference patterns may be obtained.