Polarization modulators based on liquid crystal variable retarders for the Solar Orbiter mission

摘要: A polarization modulator based on Liquid Crystal Variable Retarders (LCVRs) will be used in the Polarimetric and Helioseismic Imager (PHI) for Solar Orbiter mission to measure complete Stokes vector of incoming light. PHI is one six remote sensing instruments onboard this space led by European Space Agency (ESA) with strong NASA participation. It an imaging spectro-polarimeter that acquire high resolution solar magnetograms. Also LCVRs METIS instrument (Multi Element Telescope Imaging Spectroscopy). a coronagraph analyze linear observations visible-light K-corona. The modulators are described work including optical, mechanical, thermal electrical aspects. Both consist two identical relative azimuth orientation 45o parallel modulator. In first case, configuration allows analysis full maximum polarimetric efficiencies. second setup, wide acceptance angles (≤ ±7°) obtained. This works presents preliminary results obtained representative prototypes from verification environmental test campaign progress currently. main performances were measured analyzed efficiencies, wavefront error transmission, beam deviation transmittance. valuable information allow consolidate detailed design these devices increasing its TRL 6 proceed manufacturing Qualification Model (QM) Flight Models (FM).