Polarization-dependent vacuum-ultraviolet reflectometry using elliptically polarized synchrotron radiation

Alexander Gottwald (1) , Françoise Bridou (2) , Mireille Cuniot-Ponsard (3) , Jean-Michel Desvignes (3) , Simone Kroth (1) , Udo Kroth (1) , Wolfgang Paustian (1) , Mathias Richter (1) , Hendrik Schöppe (1) , Thornagel Reiner (1)

1 PTB - Physikalish-Technishe Bundesanstalt
2 Laboratoire Charles Fabry de l'Institut d'Optique / Scop
3 Laboratoire Charles Fabry de l'Institut d'Optique / Manolia

In the laboratory of the Physikalisch-Technische Bundesanstalt (PTB) at the Berlin electron-storage ring BESSY II, a procedure has been developed to investigate the dependence of vacuum-ultraviolet reflection on polarization. It is based on characterizing the elliptically polarized synchrotron radiation at PTB's normal-incidence monochromator beamline for reflectometry by means of polarization-sensitive photodetectors. For this purpose, the polarization dependency in the detector responsivity was determined at a small, low, solid angle of acceptance for the synchrotron radiation, i.e., within the orbital plane of the storage ring where the degree of linear polarization is known to be almost 100%. Our method allows the polarization dependence of reflection samples to be measured with relative standard uncertainties ranging from 2.4% to 11% in the spectral range between 60 and 160 nm. The method has been applied to the optimization of polarizing mirrors at the Lyman-α wavelength of 121.6 nm.

Domaines: Optique [physics.optics]

Alexander Gottwald, Françoise Bridou, Mireille Cuniot-Ponsard, Jean-Michel Desvignes, Simone Kroth, et al.. Polarization-dependent vacuum-ultraviolet reflectometry using elliptically polarized synchrotron radiation. Applied optics, 2007, 46 (32), pp.7797-7804. ⟨hal-00575921⟩