Atomic force microscopy characterization of Zerodur mirror substrates for the extreme ultraviolet telescopes aboard NASA's Solar Dynamics Observatory
- 15 May 2007
- journal article
- Published by Optica Publishing Group in Applied Optics
- Vol. 46 (16), 3156-3163
- https://doi.org/10.1364/ao.46.003156
Abstract
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.Keywords
This publication has 10 references indexed in Scilit:
- Smoothing of diamond-turned substrates for extreme ultraviolet illuminatorsOptical Engineering, 2004
- Large area smoothing of optical surfaces by low-energy ion beamsThin Solid Films, 2004
- Surface characterization techniques for determining the root-mean-square roughness and power spectral densities of optical componentsApplied Optics, 2002
- Recent developments in EUV reflectometry at the Advanced Light SourcePublished by SPIE-Intl Soc Optical Eng ,2001
- Evolution of surface topography of fused silica by ion beam sputteringApplied Surface Science, 2001
- Smoothing of mirror substrates by thin-film depositionPublished by SPIE-Intl Soc Optical Eng ,1999
- Scattering from normal-incidence EUV opticsPublished by SPIE-Intl Soc Optical Eng ,1998
- High-resolution, high-flux, user friendly VLS beamline at the ALS for the 50–1300eV energy regionJournal of Electron Spectroscopy and Related Phenomena, 1998
- Nonspecular x-ray reflection from rough multilayersPhysical Review B, 1994
- Stochastic model for thin film growth and erosionApplied Physics Letters, 1993