Plane optical element sub surface damage detecting method

Abstract

The invention discloses a plane optical element sub surface damage detecting method. The plane optical element sub surface damage detecting method comprises the steps that firstly, directional abrasive material liquid is adopted to be subject to jet flow to the surface of a plane optical element to make an observation slope, and the depth, penetrating into the plane optical element, of the observation slope should meet the requirement that the sub surface crack can be sufficiently exposed; secondly, a hydrofluoric acid solution is used for etching the observation slope, and the plane optical element is sufficiently exposed along the sub surface crack layer in the observation slope direction to be conveniently observed; thirdly, with the aid of the scanning function of a contourgraph, the profile curve of the observation slope is measured, and the included angle value between the horizontal plane and the observation slope can be obtained; fourthly, with aid of a micro motion stage and the clear imaging function of an ultra-field-depth optical microscope, the sub surface crack distribution condition in the observation slope direction can be obtained, and the moving total distance ofthe micro motion stage when the final crack disappears can be determined; fifthly, in combination with the moving total distance of the micro motion stage when the final crack disappears and the included angle value between the horizontal plane and the observation slope in the third step, the sub surface crack depth value can be calculated.

Description

Technical field [0001] The invention relates to the technical field of ultra-precision processing and detection, in particular to a method for detecting subsurface damage of a planar optical element. Background technique [0002] Plane optical components (such as plane mirrors, plane standard mirrors) are an important part of the optical system. In the optical system of the National Ignition Facility (NIF), 192 beams require a total of about 7,500 large and medium-sized optical components with a size of 420mm×420mm or more, plus backup optical components and small-aperture optical components. About 30,000 optical components. They are characterized by high-precision surface shapes, ultra-smooth surfaces, high surface / subsurface quality and large-volume requirements. It is worth noting that about 80% of the optical components in the National Ignition Device NIF are planar components (including polarizers, neodymium glass plates, mirrors, and pulse compression gratings, etc.). Onl...

AI Technical Summary

Problems solved by technology

Destructive inspection can lead to damage or failure of expensive optical components, and the inspection process is highly dependent on operator experience

Non-destructive testing methods have problems such as low measurement accuracy, shallow detection depth, unintuitive measurement results, and high cost of testing systems.

The establishment of the prediction model in the theoretical prediction method is basically based on empirical formulas, and the introduction of some assumptions makes it difficult to guarantee the accuracy of the prediction results

In addition, the application of the destructive detection methods, non-destructive detection methods and theoretical prediction methods listed above basically stays in the processing samples in the laboratory environment as the detection object, and is aimed at large and medium-sized planar optics in the background of engineering applications. Less practical for subsurface damage detection of components

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