False signature reduction in infrared channeled spectropolarimetry

Channeled spectropolarimetry, first developed by K. Oka, is capable of measuring all the Stokes parameters from a single modulated spectrum. We present a theoretical means for improving the spectral resolution of channeled spectropolarimetry by at least a factor of four. Especially valuable in the infrared due to atmospheric absorption features, this method simultaneously provides for the correction of aliasing artifacts from the channels used for the determination of the Stokes parameters. The technique is experimentally demonstrated using a Fourier transform infrared spectrometer and two multiple-order Yttrium Vanadate (YVO4) retarders. This approach is implemented with consideration of crystal dichroism effects, and reconstructions are compared with conventional channeled spectropolarimetric reconstructions from the same system. Additional results, produced by using Cadmium Sulfide (CdS) retarders, provide demonstration of the technique across the infrared.