Absolute surface shape detection device for planar optical elements

Abstract

The invention discloses a planar optical element absolute surface shape detection device. The planar optical element absolute surface shape detection device comprises a laser interferometer, a beam expanding collimation system, a transmitting mirror two-dimensional adjusting system, a reflector four-dimensional adjusting system, three planar optical element clamps, three planar optical elements, and a reflector rotation electrical appliance control system. The planar optical element absolute surface shape detection device is advantageous in that the planar optical element absolute surface shape detection is realized, and an object of improving detection precision is realized, and then a processing level is evaluated in a marked way, and therefore guiding significance is provided for further improvement of processing precision.

Description

Technical field [0001] The invention relates to a high-precision detection of a high-precision planar optical element, in particular to a detection device for the absolute surface shape of a planar optical element. It can realize the absolute surface shape detection of the full-caliber of the plane element, improve the detection accuracy, and have a landmark quantitative processing level, and achieve guiding significance for the further breakthrough of processing accuracy. Background technique [0002] At present, the requirements for detection level of optical components are getting higher and higher, especially in the projection lithography exposure optical system, the requirements for the RMS value of the surface shape of the components reach the nanometer or even sub-nanometer level, which is a very high challenge to the level of optical detection. At present, interferometry is one of the most effective high-precision optical plane measurement methods. Commonly used optical ...

AI Technical Summary

Problems solved by technology

[0003] At this stage, interferometer detection is all relative measurement, and the accuracy of interferometric detection is limited by the reference mirror shape of the interferometer itself (PV value is generally better than 0.1λ), especially when the surface quality PV of the detection element is better than 0.1λ or even higher At this time, the accuracy of the measurement results cannot be judged, and it is necessary to separate the reference mirror error to achieve absolute measurement

[0004] The current three-surface mutual detection method mostly uses polynomial fitting in the process of data processing, which loses the medium and high frequency information of the wave surface, makes the obtained plane shape information incomplete, and affects the measurement accuracy of absolute detection.

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