TABLE OF CONTENTS Katherine Creath
Optical Sciences Center
University of Arizona
Tucson, Arizona
and
James C. Wyant
Optical Sciences Center
University of Arizona
Tucson, Arizona
and
WYKO Corporation
Tucson, Arizona
| CGH | computer-generated hologram |
| M | linear, lateral magnification |
| N | diffracted order number |
| n | integers |
| P | number of distortion-free resolution points |
| r | radius |
| S | maximum wavefront slope (waves/radius) |
| x, ? x | distance |
| ? ? | rotational angle error |
| ? | wavefront phase error |
| ? | rotational angle |
| ? | wavelength |
| | wavefront phase described by hologram |
Holography is extremely useful for the testing of optical components and systems. If a master optical component or optical system is available, a hologram can be made of the wavefront produced by the component or system and this stored wavefront can be used to perform null tests of similar optical systems. If a master optical system is not available for making a hologram, a synthetic or a computer-generated hologram (CGH) can be made to provide the reference wavefront.1 10 When an aspheric optical element with a large departure from a sphere is tested, a CGH can be combined with null optics to perform a null test.
There are several ways of thinking about CGHs. For the testing of aspheric surfaces, it is easiest to think of a CGH as a binary representation of the ideal interferogram that would be produced by interfering the reference wavefront with the wavefront produced by a perfect sphere. In the making of the CGH the entire interferometer should be ray traced...
