Static Fourier transform imaging spectropolarimeter based on quarter-wave plate array

A compact, static Fourier transform imaging spectropolarimeter based on quarter-wave plate array is conceptually described. It improves a Savart interferometer by replacing front polarizer with a Wollaston prism and an aperture divided by a quarter-wave plate array, and can simultaneously acquire six interferograms corresponding to six linearly polarized lights on a single CCD. The spectral dependence of all Stokes parameters can be recovered by Fourier transform. Since there is no rotating or moving part, the system is relatively robust. The interference model is proved. The performance of the system is demonstrated through a numerical simulation. The orientation of quarter-wave plate array is optimized. Alignment errors of the elements respect to the ideal position are discussed and a procedure for compensating the alignment errors is also developed.