Abstract
Short-wavelength imaging, spectroscopy, and lithography scale down the characteristic length-scale to nanometers. This poses tight constraints on the optics finishing tolerances, which is often difficult to characterize. Indeed, even a tiny surface defect degrades the reflectivity and spatial projection of such optics. In this study, we demonstrate experimentally that a Hartmann wavefront sensor for extreme ultraviolet (XUV) wavelengths is an effective non-contact analytical method for inspecting the surface of multilayer optics. The experiment was carried out in a tabletop laboratory using a high-order harmonic generation as an XUV source. The wavefront sensor was used to measure the wavefront errors after the reflection of the XUV beam on a spherical multilayer mirror, scanning a large surface of approximately 40 mm in diameter. The results showed that the technique detects the aberrations in the nanometer range.
© 2018 Optical Society of America
Full Article | PDF ArticleMore Like This
Hugo Dacasa, Hélène Coudert-Alteirac, Chen Guo, Emma Kueny, Filippo Campi, Jan Lahl, Jasper Peschel, Hampus Wikmark, Balázs Major, Erik Malm, Domenico Alj, Katalin Varjú, Cord L. Arnold, Guillaume Dovillaire, Per Johnsson, Anne L’Huillier, Sylvain Maclot, Piotr Rudawski, and Philippe Zeitoun
Opt. Express 27(3) 2656-2670 (2019)
Dmitriy Ksenzov, Tobias Panzner, Christoph Schlemper, Christian Morawe, and Ullrich Pietsch
Appl. Opt. 48(35) 6684-6691 (2009)
Pascal Mercère, Philippe Zeitoun, Mourad Idir, Sébastien Le Pape, Denis Douillet, Xavier Levecq, Guillaume Dovillaire, Samuel Bucourt, Kenneth A. Goldberg, Patrick P. Naulleau, and Senajith Rekawa
Opt. Lett. 28(17) 1534-1536 (2003)