title: Mid-infrared optical properties of thin films of aluminum oxide, titanium dioxide, silicon dioxide, aluminum nitride, and silicon nitride.
abstract: The complex refractive index components, n and k, have been studied for thin films of several common dielectric materials with a low to medium refractive index as functions of wavelength and stoichiometry for mid-infrared (MIR) wavelengths within the range 1.54-14.29 μm (700-6500 cm(-1)). The materials silicon oxide, silicon nitride, aluminum oxide, aluminum nitride, and titanium oxide are prepared using room temperature reactive sputter deposition and are characterized using MIR variable angle spectroscopic ellipsometry. The investigation shows how sensitive the refractive index functions are to the O2 and N2 flow rates, and for which growth conditions the materials deposit homogeneously. It also allows conclusions to be drawn on the degree of amorphousness and roughness. To facilitate comparison of the materials deposited in this work with others, the index of refraction was also determined and provided for the near-IR and visible ranges of the spectrum. The results presented here should serve as a useful information base for designing optical coatings for the MIR part of the electromagnetic spectrum. The results are parameterized to allow them to be easily used for coating design.
authors.affiliation: Humboldt-Universität zu Berlin, Newtonstrasse 15, 12489 Berlin, Germany. kischkat@physik.hu‐berlin.de
authors.forename: Jan
authors.initials: J
authors.lastname: Kischkat
authors.forename: Sven
authors.initials: S
authors.lastname: Peters
authors.forename: Bernd
authors.initials: B
authors.lastname: Gruska
authors.forename: Mykhaylo
authors.initials: M
authors.lastname: Semtsiv
authors.forename: Mikaela
authors.initials: M
authors.lastname: Chashnikova
authors.forename: Matthias
authors.initials: M
authors.lastname: Klinkmüller
authors.forename: Oliana
authors.initials: O
authors.lastname: Fedosenko
authors.forename: Stephan
authors.initials: S
authors.lastname: Machulik
authors.forename: Anna
authors.initials: A
authors.lastname: Aleksandrova
authors.forename: Gregorii
authors.initials: G
authors.lastname: Monastyrskyi
authors.forename: Yuri
authors.initials: Y
authors.lastname: Flores
authors.forename: W Ted
authors.initials: WT
authors.lastname: Masselink