Fourier transform imaging spectropolarimeter using ferroelectric liquid crystals and Wollaston interferometer.

A time-division Fourier transform imaging spectropolarimeter (FTISP) for acquiring spatial, spectral, and polarized information is presented. The FTISP employs two ferroelectric liquid crystals (FLCs) and a Wollaston interferometer. The fast axes of the FLCs are controlled to switch quickly without mechanical movement, enabling the polarization state analyzer (PSA) to modulate the full set of Stokes parameters rapidly. The interferometer combines a Wollaston prism with a retroreflector, enabling high interference modulation and facilitating optical alignment. The optimal design for the FLC-PSA and Wollaston interferometer, and the Fourier transform recovery for the polarized interferogram, are presented in detail. To verify the proposed FTISP, laboratory and outdoor experiments were conducted, and the experimental results demonstrate that the proposed FTISP offers much promise for spectropolarimetric measurement with the advantages of fast speed, high spectral resolution, and high signal-to-noise ratio.