Polarizers for the Extreme Ultraviolet

Abstract

The polarizing properties of materials in the extreme ultraviolet are being studied for the purpose of developing both reflecting and transmitting polarizers. Calculations of the ratios R8/Rp=ρ and TP/T8=1/ρ have been made for some of those materials whose optical constants have been measured and an attempt was made to verify the calculated ratios experimentally where possible. The calculations indicate the possibility of making transmitting polarizers, using multilayer unbacked metal films, for wavelengths less than the critical wavelength of the metal. The calculated value of 1/ρ for Au/Al/Au at 640 Å and i=42° was found to be 15, but Tp, for this multilayer film, is only a few percent. Reflecting polarizers, which are much less convenient to use, show more complete polarization. For example, for Au/Al/Glass at 640 Å, ρ=35 at i=62°, and R8=30%.