CONFIGURABLE COMBINATION SPECTROMETER AND POLARIZER

摘要

A multimode configurable imaging spectropolarimeter in which the polarimetry function can be activated and deactivated on demand. The multimode configurable imaging spectropolarimeter comprises a first beamsplitter (420) configured to split incident electromagnetic radiation from a scene into a first optical path and a second optical path; a movable first mirror (430) positioned in the first optical path and configured to reflect electromagnetic radiation in the first optical path, the first mirror being movable over a first scan range to provide a first optical path length difference between the first optical path and the second optical path; a polarizing beamsplitter (450) positioned in the second optical path and configured to split electromagnetic radiation in the second optical path into a first polarization and a second polarization, the first and second polarizations being orthogonal to one another; a movable second mirror (440) positioned in the second optical path and configured to reflect the first polarization, the second mirror being selectively movable over a second scan range to provide a second optical path length difference between the first and second polarizations; and at least one focal plane array sensor (460) configured to receive electromagnetic radiation from the first and second optical paths and to produce a first interferogram corresponding to the first polarization and a second interferogram corresponding to the second polarization and superimposed on the first interferogram, with a frequency offset between the first and second superimposed interferograms. Configuring the imaging transform spectrometer between a spectral imaging mode and a spectropolarimetric imaging mode may be performed by deactivating the movement of the movable first mirror to configure the imaging transform spectrometer into the spectral imaging mode, and activating the movement of the movable first mirror to configure the imaging transform spectrometer into the spectropolarimetric imaging mode. Also a vibration may be imparted to one of the first and second mirrors to prevent formation of interferograms.