We have numerically optimized several broadband aperiodic normal-incidence multilayer mirrors based on Sb/B₄C for the 85 – 125 Å spectral domain for spectroscopy applications below the silicon L-edge (λ = 125 Å). Three multilayer mirrors were then synthesized. The designed multilayer structures were optimized for a maximum uniform reflectivity in the 90 – 100, 95 – 105 and 100 – 120 Å wavebands, respectively. All the Sb/B₄C multilayer mirrors were synthesized via magnetron sputtering in argon medium. The multilayers reflection spectra were evaluated with the use of a laboratory XUV spectrograph employing a laser-plasma radiation source, the mirror under study, a transmission diffraction grating and a backside-illuminated CCD matrix. The experimentally recorded spectra were compared with the theoretical ones. Numerical calculations of aperiodic Sb/B₄C multilayer structures with different layer densities are presented. Effects of lower densities and small random variations of the individual layer widths on the reflection spectra are discussed.

Date Published: 24 May 2018
PDF: 10 pages
Proc. SPIE 10677, Unconventional Optical Imaging, 106772L (24 May 2018); doi: 10.1117/12.2305926

Published in SPIE Proceedings Vol. 10677:
Unconventional Optical Imaging
Corinne Fournier; Marc P. Georges; Gabriel Popescu, Editor(s)