Kredba Jan, Psota Pavel, Stašík Marek, Lédl Vít, Veselý Lukáš, Nečásek Jakub
Opt Express. 2021 Apr 12;29(8):12531-12542. doi: 10.1364/OE.420372.
A novel radius of the curvature measurement method for optical spherical surfaces using absolute interferometry is proposed. A measurement setup is designed and built around a common-path Fizeau interferometer. The cavity length (volume of air between reference and tested surfaces) can be measured by the absolute wavelength tuning interferometry. An interconnection of data from three different tunable laser diodes (central wavelengths 780, 785 and 852 nm) allows us to measure the cavity length with uncertainty from tens to hundreds of nanometres. Once the reference radius of curvature is known/measured/calibrated, the radius of surface under test can be computed applying the value of the cavity length. The radius of curvature is measured directly in confocal position of the interferometer with relative precision of about 10 ppm. Moreover, unlike standard radius measurement by interferometry, the uncertainty of the introduced method can be optimized by selecting a suitable transmission sphere. In the paper, the method is described, tested, and verified by measuring several specimens featuring different radii of curvature. The results are analysed and furthermore compared to other measurement device.
提出了一种利用绝对干涉测量法测量光学球面曲率半径的新方法。围绕共光路斐索干涉仪设计并搭建了测量装置。腔长（参考面与被测面之间的空气体积）可通过绝对波长调谐干涉测量法进行测量。来自三个不同可调谐激光二极管（中心波长分别为780、785和852 nm）的数据相互关联，使我们能够以数十到数百纳米的不确定度测量腔长。一旦已知/测量/校准了参考曲率半径，就可以应用腔长的值来计算被测表面的半径。曲率半径在干涉仪的共焦位置直接测量，相对精度约为10 ppm。此外，与干涉测量法的标准半径测量不同，所介绍方法的不确定度可通过选择合适的透射球来优化。本文描述了该方法，并通过测量几个具有不同曲率半径的样品进行了测试和验证。对结果进行了分析，并与其他测量装置进行了进一步比较。
