The optical properties of thin films of ytterbium in the 53.6–183.6-nm spectral range are described. Yb films were deposited in ultrahigh-vacuum conditions, and their transmittance and reflectance were measured <i>in situ</i>. Transmittance measurements showed that Yb has a certain window of lower absorption at approximately 54–100 nm, which makes Yb an interesting material for filters in this difficult spectral range. The optical constants were obtained from transmittance measurements and from multiangle reflectance measurements. These are what we believe are the first reported optical measurements of fresh Yb films at wavelengths shorter than 107.8 nm. Aging studies were performed both under vacuum and in a desiccator and showed that the optical properties of Yb are strongly modified on aging.
© 2003 Optical Society of America
(120.4530) Instrumentation, measurement, and metrology : Optical constants
(260.7200) Physical optics : Ultraviolet, extreme
(260.7210) Physical optics : Ultraviolet, vacuum
(310.6860) Thin films : Thin films, optical properties
(350.2450) Other areas of optics : Filters, absorption
Juan I. Larruquert, José A. Aznárez, José A. Méndez, and José Calvo-Angós, "Optical Properties of Ytterbium Films in the Far and the Extreme Ultraviolet," Appl. Opt. 42, 4566-4572 (2003)