Offered Polarimetric modes

NaCo is equipped with 4 wire-grid polarisers and 2 Wollaston prisms that allow to perform measurements of linear polarization. The wire-grids are set 45 degrees apart one from the other. There is one Wollaston orientated at zero degree on sky (i.e. E & O-vectors are displayed along the East-West axis). The other Wollaston is rotated by 45 degrees.

With the exception of the J filter, which is positionned on the same filter wheel as the polarising ellements,
all filters and cameras can be used for polarimetric observations. Note however that is has never been tested in M'.

As of period 75, we also offer an half-wave plate allowing to make measurements without having
to rotate the instrument or change the polarising element used.