A deformable three-reflection system that uses a bare silicon carbide substrate can function as an in-line, high-throughput (>30%), 90° phase shifter in the 50–100 nm spectral range. For a given extreme ultraviolet wavelength, an aluminum thin film can be deposited on the silicon carbide substrate to suppress the parallel (p) or perpendicular (s) polarization on single reflection or to introduce quarter-wave retardation and equal reflectances for incident p- and s-polarized light.
R. M. A. Azzam and A. M. Kan’an, "Extreme ultraviolet polarizing optics using bare and aluminum-coated silicon carbide," Appl. Opt. 34, 6438-6442 (1995)