Snapshot hyperspectral imaging polarimetry with full spectropolarimetric resolution

By integrating spectrally-modulated polarimetry into the optically replicating and remapping imaging spectrometer (ORRIS), a snapshot optically replicating and remapping imaging spectropolarimeter (ORRISp) is presented and analyzed. While spectrally-modulated polarimetry uses cascaded polarimetric modulation elements to encode the spectral dependence of Stokes parameters into a single spectrum, the ORRIS combines a focal-plane continuous variable filter with a staircase-grid lenslet array to directly acquire the encoded spectra from a two-dimensional (2D) scene. An iterative loop of two-step least-squares algorithm, with the capability of maintaining the intrinsic spectral resolution of the ORRIS and implementing auto-calibration, is employed to recover the spectrally-resolved Stokes parameters from the encoded spectra of the 2D scene. The build of a compact proof-of-principle prototype of the ORRISp and its operation are presented in addition to the image processing, system calibration, and reconstruction techniques. The ORRISp prototype's spectral and spectropolarimetric imaging performances are demonstrated from the laboratory and outdoor tests. The prototype can cover the spectral range of 450 - 750 nm with 56 spectral and spectropolarimetric channels, and operates over a ± 5.8° field of view with a spatial resolution of 400 × 400 pixels. It has the capability of capturing spatially- and spectrally-resolved Stokes parameters over the 2D scene in a single shot and operating at video rate.