Method for assembling microobjective on point-diffraction interferometer

Abstract

A method for assembling a microobjective on a point-diffraction interferometer belongs to an interference measuring technology field. The assembling method comprises the following steps: fixing the microobjective on a main lens cone, adjusting an optical axis of the microobjective and a rotation shaft of a high precision lathe till the optical axis and the rotation shaft are superposed and turning an inner circle of the main lens cone; making that an excircle of a meniscus lens cone and an optical axis of a meniscus lens are coaxial; replacing an aperture plate by using an optical flat; making that the excircle of an optical flat seat is parallel to the optical axis of the optical flat; installing the meniscus lens and the optical flat into the main lens cone, pressing tightly through a clamping ring so that the microobjective, the meniscus lens and the optical axis of the optical flat are superposed and the assembling is completed; after reconstruction is completed, installing the aperture plate on a three-dimensional precision adjusting table and making the optical axis which is used to reconstruct the microobjective pass through the aperture on the aperture plate. The inventionbelongs to an improved invention. The commercialized microobjective is used to perform the reconstruction so that a processing period can be substantially shortened, processing cost can be greatly reduced and an image quality can be guaranteed.

Description

technical field [0001] The invention relates to the technical field of interference measurement, in particular to a method for assembling a microscopic objective lens in a point diffraction interferometer. Background technique [0002] With the rapid development and application of high-precision precision optical instruments, the requirements for the imaging quality of optical systems are getting higher and higher, especially in the application of extreme ultraviolet lithography (EUVL), the working wavelength is 13-14nm, and the processing and testing of optical components The technology is more demanding than conventional optical systems. In order to ensure the imaging quality of the optical system, it has become a very important link to accurately detect the surface shape accuracy of the optical element and the wave aberration of the optical system. [0003] Based on the principle of interferometry, many kinds of interferometers have been developed. Common two-beam inter...

AI Technical Summary

Problems solved by technology

If the thickness of the small orifice plate in the point diffraction interferometer is thin, the use of commercial microscope objective lens has little effect on the image quality, but the mechanical strength of the small orifice plate is low, and the small orifice plate is not conducive to clamping and easy to damage; If the thickness of the orifice plate is thicker, the mechanical strength of the small orifice plate will increase, and the small orifice plate will be easy to clamp and will not be easily damaged. However, the use of commercial microscope objectives will greatly affect the image quality, and the diffusion spots will increase rapidly; Process tapered holes on the small orifice plate to reduce the thickness of the light-transmitting part of the small orifice plate. Although the influence of the thickness of the small orifice plate on the imaging quality is reduced, the processing is very difficult, and the quality of the surface shape will affect the spherical surface of the small hole. Wave quality makes a big difference

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