MEASUREMENT OF OBJECT DIMENSIONS IN COHERENT LIGHT USING THE FRESNEL TRANSFORM
Yu.V.Chugui, N.A.Yakovenko, and M.D.Yaluplin
Krasnodar-Novosibirsk
Pages: 30-44
Abstract
Accuracy characteristics of the optical method for object dimension measurement on the basis of Fresnel diffraction patterns are considered. The effect of nonuniform illumination of an object inspected on the accuracy of determining its boundaries is analytically estimated. An effective algorithm for reducing the measurement error (caused by this effect) is proposed. It takes into account values of the amplitude and derivative of the illuminating field in the neighborhood of object boundaries and, thus, reduces the error by a factor of several tens.
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