Transient X-ray Spectroscopy & Diffraction
Max Planck Research Group Michael Zürch
Transient X-ray Spectroscopy & Diffraction
Max Planck Research Group Michael Zürch

News Post
Paper on the Retrieval of the complex-valued refractive index of germanium near the M4,5 absorption edge published
Jun 1 2019

Our paper “Retrieval of the complex-valued refractive index of germanium near the M4,5 absorption edge” has been published in the Journal of the Optical Society of America B. In this work we show that the complex-valued index of refraction of germanium in the extreme ultraviolet (XUV) is measured by multi- angle reflectance of synchrotron radiation. The resulting index of refraction is higher resolution than previously measured values. It reveals new structures attributed to transitions from the 3d-core orbitals to the Σ5c,2 and the X5c,2 conduction bands. Additionally, we show that the problem of total external reflection, which renders multi-angle reflectance measurements insensitive to the complex-valued refractive index at grazing incidence, can be overcome by employing measurements at angles of incidence away from the critical angle.

Retrieved complex refractive index. (a) Retrieved κ (red,
solid) compared to previous studies, along with error (red, shaded).
(b) Retrieved n (blue, solid), compared to previous studies, along with
error (blue, shaded). Because of the small error in n, shaded error bars
appear on top of the data.
Original link to the journal:
https://www.osapublishing.org/josab/abstract.cfm?uri=josab-36-6-1716