The MuSiCoS Polarimeter:
the Focal Reducer
Focal reducer of the MuSiCoS polarimeter. In the left panel,
the Cassegrain beam comes from the top and the horizontal line at the bottom depicts
the focal plane of the double fibre. R1 and R2 note the curvature radii of the upper
and lower surface of each lens respectively. The multicolour spot
diagram (right panel) is smaller than 5 microns (each axis tick
corresponds to 0.5 micron) for object off-axis distances of 0 (bottom), 335 (middle)
and 670 microns (top).