The Liquid Crystal based Stokes Polarimeter (LCSP) was developed for high resolution full Stokes spectropolarimetry of solar vector magnetic fields. A prototype version was operated at the Gregory Coud? Telescope (GCT) at the Observatorio del Teide (Tenerife). The low voltage polarimeter consists of two nematic crystal variable retarders in front of a polarizing beam splitter. The voltage tunable variable retardance of the crystals is used for the in situ compensation of cross-talk inside the polarimeter. Other parts of instrumental polarization are removed by a method using the full spectral information contained in the observed Stokes profiles.
"Liquid-crystal-based Stokes polarimeter", Proc. SPIE 4133, Polarization Analysis, Measurement, and Remote Sensing III, (15 November 2000); doi: 10.1117/12.406640; https://doi.org/10.1117/12.406640