Soufli Regina, Baker Sherry L, Windt David L, Gullikson Eric M, Robinson Jeff C, Podgorski William A, Golub Leon
Lawrence Livermore National Laboratory, Livermore, California 94550, USA.
Appl Opt. 2007 Jun 1;46(16):3156-63. doi: 10.1364/ao.46.003156.
The high-spatial frequency roughness of a mirror operating at extreme ultraviolet (EUV) wavelengths is crucial for the reflective performance and is subject to very stringent specifications. To understand and predict mirror performance, precision metrology is required for measuring the surface roughness. Zerodur mirror substrates made by two different polishing vendors for a suite of EUV telescopes for solar physics were characterized by atomic force microscopy (AFM). The AFM measurements revealed features in the topography of each substrate that are associated with specific polishing techniques. Theoretical predictions of the mirror performance based on the AFM-measured high-spatial-frequency roughness are in good agreement with EUV reflectance measurements of the mirrors after multilayer coating.
在极紫外（EUV）波长下工作的镜子的高空间频率粗糙度对反射性能至关重要，并且要符合非常严格的规格要求。为了理解和预测镜子性能，需要精密计量来测量表面粗糙度。利用原子力显微镜（AFM）对由两家不同抛光供应商制造的、用于一套太阳物理EUV望远镜的Zerodur镜坯进行了表征。AFM测量揭示了每个镜坯表面形貌中与特定抛光技术相关的特征。基于AFM测量的高空间频率粗糙度对镜子性能的理论预测与多层镀膜后镜子的EUV反射率测量结果吻合良好。
