@proceedings{12302,
  author = {Felix Widmann and Frank Eisenhauer and Oliver Pfuhl and Nicolas Schuhler and Xavier Haubois and A. Amorim and Michi Baubock and Wolfgang Brandner and Jason Dexter and feng gao and Paulo Garcia and Reinhard Genzel and Stefan Gillessen and Alejandra Jimenez-Rosales and Sylvestre Lacour and Thomas Ott and Karine Rousselet-Perraut and Guy Perrin and Jinyi Shangguan and Odele Straub and Christian Straubmeier and Eckhard Sturm and Sebastiano von Fellenberg},
  editor = {Antoine Mérand and Stephanie Sallum and Peter Tuthill},
  title = {Polarization analysis of GRAVITY and the VLTI},
  abstract = {Instrumental polarization can have large effects on measurements with the VLTI, as it can alter measured polarization and introduce uncertainties. To understand these effects we measured and simulated the instrumental polarization of the VLTI and of GRAVITY. We are able to provide a calibration model for GRAVITY observations and quantify systematic uncertainties due to instrumental polarization. This work has shown to be crucial to measure the polarization of the galactic center black hole Sgr A* where we detect a swing in the polarization angle during flare events. While the analysis was done for GRAVITY, it also gives an important basis for the design of future near-infrared instruments at the VLTI.},
  year = {2020},
  journal = {Optical and Infrared Interferometry and Imaging VII},
  volume = {11446},
  edition = {Optical and Infrared Interferometry and Imaging VII},
  pages = {online only},
  month = {2020-12},
  publisher = {SPIE},
  isbn = {9781510636798},
  doi = {10.1117/12.2559311},
}