Precision Measurement of Complex Optics Using a Scanning‑Point Multiwavelength Interferometer Operating in the Visible Domain  

作　　者：Marc Wendel 

机构地区：[1]Ametek GmbH/BU Taylor Hobson,Rudolf-Diesel-Str.16,64331 Weiterstadt,Germany

出　　处：《Nanomanufacturing and Metrology》2023年第2期19-26,共8页纳米制造与计量（英文）

摘　　要：The growing demands of optical systems have led to increasingly complex aspheres and freeforms.In this paper,an established measurement system in asphere production,which is also a promising approach in high-precision freeform metrology,is presented.It is based on a scanning-point multiwavelength interferometer approach.The scanning principle enables great fexibility,reduces setup time and costs,and has almost no limitations in spherical departure.Due to the absolute measurement capability,the utilized multiwavelength approach is benefcial for segmented,annular,and discrete surfaces,which are common designs of modern applications’optical elements.The metrology system enables measurements on a nanometer scale on a great variety of apertures—from 1 to 1000 mm.Recently,a new short-coherence multiwavelength interferometer operating in the visible domain has been developed.It enables the high-precision measurement on silicon-coated surfaces,which can be found in space applications and are also commonly used for extreme-ultraviolet(EUV)lithographic setups,which will be used as an example throughout this work.Owing to the large absolute measurement capability,applied grating structures for suppressing infrared light in the EUV process can easily be measured.This paper summarizes the basic working principles of the proposed metrology system,explains the special requirements for diferent felds of application,highlights the capabilities of the visible multiwavelength approach,and shows the measurement results.

关 键 词：Multiwavelength interferometer Scanning-point sensor Metrology Short coherence interferometry 

分 类 号：TP212[自动化与计算机技术—检测技术与自动化装置]