Detection device of subsurface defect of optical element and method thereof

Abstract

The invention provides a detection device of subsurface defect of an optical element with little measurement error and a method thereof. The detection device of the subsurface defect of the optical element comprises a microscope, a precise displacement platform and an image data processing unit connected with the microscope, wherein thethe image data processing unit is further connected with a laser displacement sensor which is used for measuring the movement amount of the precise displacement platform in the direction Z. In the invention, the optical microscope and the laser displacement sensor are adopted for measuring the subsurface detect, the subsurface defect depth and the appearances of the subsurface detect under different depths are obtained, and the observation of the appearances of the subsurface detect under different depths and the accurate depth measurement are realized, error resulting from the reposition of the traditional detection is avoided, and micron-level measurement precision is ensured. The invention is used for the detection of the subsurface defect of optical glass, and is suitable for the measurement of processing subsurface defect of ceramic, silicon, germanium and other engineering materials.

Description

technical field [0001] The invention relates to the field of optical processing and detection, in particular to a detection device and method for subsurface defects generated in the processing and grinding stages of optical elements. Background technique [0002] With the development of large-scale laser optical systems, astronomical telescopes and space telescope systems, the requirements for the processing quality of optical components are becoming more and more stringent. Over the years, studies on the causes of defects in optical components have shown that subsurface defects such as microcracks generated during the manufacturing process of optical components are important factors that cause defects in optical components. The lifetime and performance of optical components in optical systems are affected by their processing quality, especially subsurface defects. Therefore, accurate and effective measurement of the degree and depth of subsurface defects in optical compone...

AI Technical Summary

Problems solved by technology

In this method, the ground sample is first partially polished and etched, and then the profiler is used to measure the surface profile of the side area along a certain direction from the grinding area to the polishing area to obtain the shape of the measured area, that is, the depth Z( Height) changes with the X (horizontal) direction, and then use a microscope to observe the same area. When observing, the microscope observation area must be completely consistent with the profiler measurement area, and the coordinates in the X direction must be known. This involves the sample under the microscope. The repositioning of the microscope and the displacement accuracy of the microscope in the X direction lead to large errors in the measurement results, which eventually lead to unreliable depth and shape measurement results

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