A method for measuring the surface profile of a linear white light

Abstract

The invention relates to a method for measuring the surface profile of a line white light. A slit diaphragm is set in the imaging optical path, and only one rectangular light strip passes through the slit to irradiate the measured sample. The image of only has a rectangular white band in the middle, and the rest is black. When the interference image generated by the measurement system is truncated by the slit diaphragm, there are only some interference fringes on the rectangular leucorrhea. When measuring objects of different heights, the interference fringes on the rectangular leucorrhea will shift laterally with different measured heights. , through the measurement of the rectangular leucorrhea in the field of view, the midpoint along the rectangular leucorrhea is regarded as the reference point, and the lateral movement of the coherence peak of the interference fringe in the rectangular leucorrhea is expressed as the height in the vertical direction, and is matched with the displacement of the external shaft system The platform realizes the tracking and scanning measurement of the surface profile.

Description

Technical field [0001] The present invention relates to a new type of white light surface profile measurement method. Background technique [0002] It is well known that the performance of the spherical optical system is limited by aberration. Applying aspherical and free curved surface optics, minimizing or even eliminating geometric aberrations while reducing the number of components, sizes, and overall system. Aspherical and free surfaces have a wide range of applications in Blu-ray players, mobile phones and digital cameras, infrared optical imaging, laser diodes, and LED collimated optical, fiber optic couplers, artificial crystals. In recent years, the new optical processing technology has developed rapidly due to the demand of this complex optical surface. At the same time, various applications have also proposed increasingly high-quality requirements for their adequacy, and the measurement requirements of these parts are also urgent. In order to obtain the optimal use of ...

AI Technical Summary

Problems solved by technology

At present, the mainstream of nanometer-scale measurement of complex optical surfaces is still centering on focal point scanning and surface interferometry, which is reflected in the successive appearance of advanced high-precision measurement equipment such as NANOMEFOS, Luphoscan, and white light interferometers. However, the cost of these advanced equipment is very high. Expensive, large volume, and there are certain limitations in the measurement of complex surfaces with large curvature

Conventional point scanning measurement requires complex photoelectric coordination to achieve nanometer-level measurement accuracy. The measurement accuracy depends on the stability and accuracy of the overall system, and the measurement efficiency is low. The overall system is large in size and expensive.

Surface interferometry has nanometer-level measurement accuracy, but interferometry is easily affected by external disturbances. For the measurement of large-area complex optical surfaces, sub-aperture splicing is required, and splicing errors affect measurement accuracy.

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