Stokes-spectro-polarimetry with a two-dimensional diode array

A new apparatus is described which measures the Stokes profiles by means of a two-dimensional 100 × 100 detector array. On-line data processing allows the immediate visualization of the profiles corresponding to several spectral lines observed simultaneously along one spatial direction on the solar disk. An improved method for the accurate compensation of the telescopic birefringence with a Bowen compensator is realized. Three different methods for the investigation of fluxtube properties are discussed, based on the analysis of V profiles and illustrated by first measurements with the apparatus. Two characteristics of V profiles; excess polarization and zero crossing wavelength of the V profile show strong spatial variations in plages and network indicating different dynamical conditions for individual fluxtubes.