| Shack-Hartmann wavefront sensor test of multi-component lens with a flat mirror internal illumination |
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Setup:
In the above configuration, light from Optino, it comes to a focus at F (which is also the radius of curvature of the spherical mirror). It falls on the spherical mirror, and retraces its path, passing though Optino again, going through the SH system.
The aberrations of the SH system itself are removed taking a calibration frame of a small high quality spherical mirror instead of the lens L. This determines the accuracy of the test.
The spherical aberration of a mirror at its center of curvature is given by:
Here ASA is the angular spherical aberration (diameter of image at best focus – in radians), K the conic coefficient of the mirror, r the ray height on the mirror, and R the radius of curvature. Spherical mirrors have zero ASA (K =0), while parabolic (K =-1) and hyperbolic (K <-1) mirrors have large positive spherical aberration. However, Sensoft is capable of testing mirrors with hundreds of wavelengths of aberrations.
The accuracy of the tests depends on the quality of the spherical mirror S and the flat mirror used for the calibration.
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| Lenses |
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| Mirrors |
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 spherical mirror |
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Ophthalmic lenses |
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| Human eye |
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| Astronomical Telescopes |
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