First Results from ZIMPOL II

  • Achim M. Gandorfer
Part of the Astrophysics and Space Science Library book series (ASSL, volume 243)


We present an imaging polarimeter for the full Stokes vector (I,Q,U,V), based on fast polarization modulation and demodulation by a CCD sensor. In the second generation Zurich Imaging Polarimeter ZIMPOL II ferroelectric liquid crystals modulate the Stokes vector at a frequency of 1 kHz. A special CCD sensor is used as part of a synchronous demodulator. For the first time simultaneous high accuracy polarimetric measurements of the complete Stokes vector with a single CCD are possible. The Stokes vector images do not suffer from gain-table or flatfield effects. Seeing noise is avoided by the fast modulation frequency. The polarimetric efficiency is 0.71 for all polarized Stokes parameters. The useful wavelength range is 1000 Å with one modulator package. First results of this new instrument are presented and analysed to experimentally evaluate the performance of the system.

Key words

instrumentation: polarimeters array detectors ferroelectrics 


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Copyright information

© Springer Science+Business Media Dordrecht 1999

Authors and Affiliations

  • Achim M. Gandorfer
    • 1
  1. 1.Institute of AstronomyETH ZentrumZurichSwitzerland

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