[1999] Efficient testing of off-axis aspheres with test plates and computer-generated holograms

Burge, James H. “Efficient testing of off-axis aspheres with test plates and computer-generated holograms.” Optical Manufacturing and Testing III. Vol. 3782. SPIE, 1999.

Abstract:

Off axis aspheric surfaces, such as individual segments for a telescope mirror, and surfaces that do not have any optical axis are traditionally difficult to test. In addition to difficulties controlling the aspheric shape, mirror segments have tight on radius of curvature and optical axis position. This paper presents a new method of measuring these surfaces that uses a test plate with a spherical reference surface, in combination with a small computer generated hologram to compensate the aspheric departure. The example for measuring 1.8-m segments of a 10-m primary mirror is given.

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