RECENT PROGRESS IN IMAGING POLARIMETRY

Recent instrumental developments in imaging polarimetry allow array de tectors to reach a polarimetric sensitivity of 1 x 10(-4) of the inten sity. New instrumental effects appear at these levels of sensitivity a nd generate spurious polarization signals with amplitudes of up to 5 x 10(-4). Here I discuss these effects and present methods to avoid the m. Polarized spectra with an rms noise of 6 x 10(-6) may then be obtai ned. Furthermore a method is brought to the reader's attention that al lows polarization measurements at the 1 x 10(-4) level with regular ar ray detectors, e.g, in the near-infrared.