Parameter Determination Method in Inclined Wavefront Interferometry Aspheric Surface

Abstract

The invention belongs to the field of optical precision testing and specifically relates to an aspheric surface parameter determining method in tilted-wave interferometer. The method includes steps of1, according to a given aspheric equation and diameter, dividing an aspheric surface evenly according to an angle; setting the center of incoming spherical waves and calculating mirror points of thecenter of the spherical wave relative to each node by utilizing a formula; emitting light to corresponding node coordinate positions from the mirror points so as to form a reflection wave face, judging a distribution range of measurable interference fringes according to the phase difference distribution between the calculated reflection wave face and reference spherical waves, moving the positionof the center of the spherical waves, repeating the above process until the whole aspheric surface can be measured; therefore, positions of all the spherical wave sources are determined and design ofa point source array is implemented. The method is clear in steps, accurate in calculation and wide in application range; by using a computer program, design can be made quickly; approximate evaluation is not needed during the calculation process and the calculation result is accurate.

Description

technical field [0001] The invention belongs to the field of optical precision testing, and in particular relates to a method for determining parameters in inclined wavefront interferometric measurement of aspheric surfaces. Background technique [0002] In a rotationally symmetric optical system, the use of aspheric elements can reduce the number of elements in the system while achieving higher performance. However, the measurement of an aspheric surface is much more difficult than that of a spherical surface. Interferometry is a common method for measuring the surface shape of optical components. In the test of a spherical surface, a higher-precision spherical surface can be processed to achieve zero position measurement. In the measurement of an aspheric surface, it must be based on the aspheric surface to be measured. For the spherical equation, only by processing an aspheric surface with the same surface shape but higher precision can the zero position measurement be r...

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Problems solved by technology

However, the measurement of aspheric surfaces is much more difficult than that of spherical surfaces

Interferometry is a common method for measuring the surface shape of optical components. In the test of a spherical surface, a higher-precision spherical surface can be processed to achieve zero position measurement. In the measurement of an aspheric surface, it must be based on the aspheric surface to be measured. Spherical equation, only by processing an aspheric surface with the same surface shape but higher precision can the zero position measurement be realized. Obviously, this method is impossible

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