Direct measurement of the complex refractive index of thin foils in the XUV spectral range by point diffraction interferometry

作者：Hemmers D^*; Benzid M; Pretzler G

来源：Applied Physics B: Lasers and Optics , 2012, 108(1): 167-175.

DOI：10.1007/s00340-012-5083-9

In this paper, we demonstrate the application of point diffraction interferometry to determine the complex refractive index of thin foils in the extreme ultraviolet spectral range. Results are cross-checked by an independent interferometric measurement of the refractive index and a direct transmission measurement of the foils. As the light source, we apply high-order harmonics of a titanium-sapphire laser generated in a gas jet. This interferometric method has the advantage to simultaneously and directly deliver the refractive and absorptive part of the refractive index without relying on the Kramers-Kronig relations or the Fresnel equations. We present results for a set of materials (aluminum, silicon, germanium, boron, and parylene), which are of interest for the design of bandpass filters or multilayer coatings.

• 出版日期2012-7