title: A synchrotron-radiation-based variable angle ellipsometer for the visible to vacuum ultraviolet spectral range.
abstract: A rotating analyzer spectroscopic polarimeter and ellipsometer with a wide-range θ-2θ goniometer installed at the Insertion Device Beamline of the Metrology Light Source in Berlin is presented. With a combination of transmission- and reflection-based polarizing elements and the inherent degree of polarization of the undulator radiation, this ellipsometer is able to cover photon energies from about 2 eV up to 40 eV. Additionally, a new compensator design based on a CaF2 Fresnel rhomb is presented. This compensator allows ellipsometric measurements with circular polarization in the vacuum ultraviolet spectral range and thus, for example, the characterization of depolarizing samples. The new instrument was initially used for the characterization of the polarization of the beamline. The technical capabilities of the ellipsometer are demonstrated by a cohesive wide-range measurement of the dielectric function of epitaxially grown ZnO.
authors.affiliation: Leibniz-Institut für Analytische Wissenschaften - ISAS - e.V., 12489 Berlin, Germany.
authors.forename: M D
authors.initials: MD
authors.lastname: Neumann
authors.affiliation: Leibniz-Institut für Analytische Wissenschaften - ISAS - e.V., 12489 Berlin, Germany.
authors.forename: C
authors.initials: C
authors.lastname: Cobet
authors.affiliation: Physikalisch-Technische Bundesanstalt, Abbestr. 2-12, 10587 Berlin, Germany.
authors.forename: H
authors.initials: H
authors.lastname: Kaser
authors.affiliation: Physikalisch-Technische Bundesanstalt, Abbestr. 2-12, 10587 Berlin, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Kolbe
authors.affiliation: Physikalisch-Technische Bundesanstalt, Abbestr. 2-12, 10587 Berlin, Germany.
authors.forename: A
authors.initials: A
authors.lastname: Gottwald
authors.affiliation: Physikalisch-Technische Bundesanstalt, Abbestr. 2-12, 10587 Berlin, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Richter
authors.affiliation: Leibniz-Institut für Analytische Wissenschaften - ISAS - e.V., 12489 Berlin, Germany.
authors.forename: N
authors.initials: N
authors.lastname: Esser