In-situ stitching interferometric test system for large plano optics

Abstract

In-situ testing is an ideal technology for improving the precision and efficiency of fabrication. We developed an in-situ subaperture stitching interferometric test system for large plano optics in the workshop environment with high precision and satisfactory repeatability. In this paper, we provide a brief account of this system and the principle of in-situ subaperture stitching measurement. Several validation tests are presented, which demonstrate that the developed system is capable of realizing in-situ testing. The size of optical flats can be measured is up to 420 mm × 780 mm, and repeatability is smaller than 0.03λ. The paper also discusses the necessary requirements for a suitable workshop environment for ensuring that the tests are stable and reliable.

Keywords

In-situ measurement / Subaperture stitching / Dynamic interferometry / Large plano optics

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Funding

National Natural Science Foundation of China http://dx.doi.org/10.13039/501100001809(51175318)

National key research and development project(2016YFF0101905)