Real-time imaging spectropolarimeter based on an optical modulator

摘要

An imaging spectropolarimeter for measuring the polarization and spectral content and the spatial signature of a target scene. The imaging spectropolarimeter includes an objective optic for receiving an electromagnetic signal and a modulator for modulating the electromagnetic signal The amplitude of each frequency component of the resulting modulated electromagnetic signal is a function of the particular polarization state of each frequency component of the electromagnetic signal. A linear polarizer passes a single polarization of the modulated electromagnetic signal to a tunable filter, which is tunable through a frequency spectrum. The tunable filter outputs a plurality of electromagnetic signal samples at predetermined frequency increments. A focal plane array receives each electromagnetic signal sample and outputs a spectrum signal and a processor applies Fourier transformation to the spectrum signal to obtain at least one Stokes polarization vector component for each pixel within the scene.