Interferometer with compound optics for measuring cylindrical objects at oblique incidence

摘要

Compound diffractive optics are used in an interferometer for simultaneously measuring multiple surfaces, making multiple measurements of individual surfaces, conveying test beams multiple times, and aligning pairs of the diffractive optics with each other. Typically, the compound optics have multiple diffraction zones that reshape test beams for reflecting from test surfaces or for combining with reference beams. The multiple diffraction zones can also exhibit different optical qualities such as transmission and reflection for conveying the test beams to and from the test surfaces.