SPHERE ZIMPOL: Overview and performance simulation
Ground-based and airborne instrumentation for astronomy II: 23-28 June 2008, Marseille, France.
C. Thalmann; H.M. Schmid; A. Boccaletti; D. Mouillet; K. Dohlen; R. Roelfsema; M. Carbillet; D. Gisler; J.-L. Beuzit; M. Feldt; R. Gratton; F. Joos; C.U. Keller; J. Kragt; J.H. Pragt; P. Puget; F. Rigal; F. Snik; R. Waters; F. Wildi
The ESO planet finder instrument SPHERE will search for the polarimetric signature of the reflected light from extrasolar planets, using a VLT telescope, an extreme AO system (SAXO), a stellar coronagraph, and an imaging polarimeter (ZIMPOL). We present the design concept of the ZIMPOL instrument, a single-beam polarimeter that achieves very high polarimetric accuracy using fast polarization modulation and demodulating CCD detectors. Furthermore, we describe comprehensive performance simulations made with the CAOS problem-solving environment. We conclude that direct detection of Jupiter-sized planets in close orbit around the brightest nearby stars is achievable with imaging polarimetry, signal-switching calibration, and angular differential imaging.