Patent ID: 6714308
Filing Date: 2004-03-30
Classification: G01B,H05K,Y10T

Abstract:
An interferometric method for measuring rotationally and non-rotationally symmetric optics, said interferometric method comprising the steps of:scanning at least one aspheric reference surface with a spherical reference surface to determine the shape of said aspheric reference surface; aligning a test optic to be measured with said aspheric reference surface placed closely adjacent the test optic by a predetermined distance; illuminating said at least one reference aspherical surface with a beam having a predetermined wavefront such that part of said predetermined wavefront is reflected from said reference aspherical surface to serve as reference wavefront and part is transmitted as a continuing aspherical wavefront that impinges on the said test optic and returns therefrom as a measurement wavefront that travels back towards said reference aspherical surface; and combining said reference and measurement wavefronts to form an interferogram containing phase information indicative of the shape of the wavefront generated by the test optic.