Spatial characterization of the focus produced by an EUV Schwarzschild objective

22nd International Congress on X-Ray Optics and Microanalysis

Ewald, Johannes^1 ; Wieland, Marek^2 ; Nisius, Thomas^1 ; Henning, Lars^1 ; Feigl, Torsten^3 ; Drescher, Markus^2 ; Wilhein, Thomas^1

Institute for X-Optics, University of Applied Sciences Koblenz, Joseph Rovan Allee 2, 53424 Remagen, Germany^1

Institute for Experimental Physics, University of Hamburg, Luruper Chaussee 149, 22761 Hamburg, Germany^2

OptiX Fab., OptiX Fab GmbH, Hans-Knoell-Straße 6, 07745 Jena, Germany^3

关键词: Current configuration;    Diffraction limited;    High harmonic generation;    Large aperture;    Numerical aperture;    Schwarzschild objective;    Spatial characterization;    Spectral range;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/499/1/012008/pdf
DOI  :  10.1088/1742-6596/499/1/012008

来源: IOP

【 摘 要 】

Schwarzschild objectives are used in the EUV spectral range because of their large aperture, high mechanical stability and excellent achromaticity. The large aperture results in a small, theoretically diffraction limited focus diameter with ideal values of below 200 nm with the current configuration. We employed a zone plate with matched numerical aperture (0.19) to image the focus onto an X-ray CCD camera. Emission from high harmonic generation and a liquid-jet laser-plasma were used as light sources. Images at magnifications of about 150-fold were acquired and focus diameters of 300 nm (FWHM) were observed.