23 July 1993 Red and blue shifts in the near field of a diffractive medium
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Proceedings Volume 1983, 16th Congress of the International Commission for Optics: Optics as a Key to High Technology; 1983AI (1993) https://doi.org/10.1117/12.2308797
Event: 16th Congress of the International Commission for Optics: Optics as a Key to High Technology, 1993, Budapest, Hungary
Abstract
As the design of contact eye lenses becomes more sophisticated it also becomes desirable to have an accurate measure of the shape of both the lens surfaces. The use of stylus instruments is undesirable because of the risk of leaving permanent marks or damage to the surface and the slow speed of measurement. The interferometrically based techniques are generally unsuitable due to the difficulty of obtaining an independent measure of shape of each surface without the effect of the other or the refractive material of the lens. Also the dimensions and gradients of the lenses are out of range for most commercially available optically based relief measuring instruments. To overcome these problems a projected fringe, phase-profilometry technique' has been extended and adapted for precision measurement of lens shape. A dynamic range of 1500:1 in relief measurement has been achieved by the combination of better quality gratings, the use of phase unwrapping procedures and improved coating of surfaces. The asphericity of the lens surface is evaluated by subtracting a fitted spherical surface from the measured relief. As an example, the results for a contact lens are presented.
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Norbert Lauinger, Norbert Lauinger, } "Red and blue shifts in the near field of a diffractive medium", Proc. SPIE 1983, 16th Congress of the International Commission for Optics: Optics as a Key to High Technology, 1983AI (23 July 1993); doi: 10.1117/12.2308797; https://doi.org/10.1117/12.2308797
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