SPECTROPHOTOPOLARIMETER BASED ON MULTIPLE REFLECTIONS IN A COATED DIELECTRIC SLAB

A division-of-amplitude photopolarimeter is described that uses multip le reflections inside a coated dielectric slab at oblique incidence. T he first four parallel reflected beams pass through suitably oriented, but fixed, linear analyzers and are intercepted by linear photodetect or arrays for spectroscopic polarimetry and ellipsometry. A particular design is presented that uses a parallel-plane fused-silica slab whic h is coated with an opaque reflecting layer of Ag or Al on the back si de and with a transparent ZnS thin film on the front side. Sufficient power is available in the high orders and the instrument matrix is non -singular, so that all four Stokes parameters of the input light can b e measured simultaneously, over the visible and near-visible spectral range. (C) 1998 Elsevier Science S.A.