Point diffraction interferometer

Abstract

The invention provides a point diffraction interferometer and comprises a light source module, a mask which can produce an ideal spherical wave, an optical diffraction component which can produce multi-level sub-diffraction light, an image sensor and an optical component. The measured optical component is arranged between the mask and the optical diffraction component and the diffraction light of some levels can permeate the optical component completely, wherein, the diffraction light of a certain level can permeate the optical component partly while being diffracted partly; the diffraction light of some levels can permeate the optical component completely, wherein, the diffraction light of a certain level can be diffracted or the optical component consists of a plurality of windows and a plurality of small holes; diffraction light of some levels can selectively permeate the window, however, the non-diffracted light can be diffracted through the small hole on the optical component. The point diffraction interferometer of the invention conducts measurement through a plurality of interference graphs which are produced at the same time and the sampling frequency is improved, moreover, the design and operation of the whole system is simplified and the motion error of a phase-shift component can be avoided.

Description

technical field [0001] The invention relates to a wave aberration measurement technology of an optical system, in particular to a point diffraction interferometer for measurement through multiple interference images generated simultaneously. Background technique [0002] The detection of optical components and systems is an important and indispensable link in optical processing. In recent years, with the continuous development of optical technology, the requirements for the precision of optical instruments have been continuously improved. In order to meet this precision requirement, optical design puts forward higher requirements on the surface precision of optical components. A basic principle in optical processing is that the accuracy of optical processing cannot exceed the detection accuracy. With the continuous development of optical processing technology, optical inspection capability has become the bottleneck of high surface precision optical element processing. At ...

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Problems solved by technology

[0007] However, in the above-mentioned prior art, the phase shift is generated by moving the grating or other beam splitting devices, so the measurement results are easily affected by the environment

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