Patent ID: 6646743
Filing Date: 2003-11-11
Classification: G01J

Abstract:
A method for determining spectral content of electromagnetic radiation comprising:passing linearly polarized electromagnetic radiation through a rotator, the rotator being an element exhibiting wavelength dependent dispersion of a polarization angle which rotates a polarization plane of all spectral components of the electromagnetic polarized radiation by an angle determined by both a wavelength of the polarized electromagnetic radiation and a physical and/or geometric characteristic of the rotator represented by a parameter p, the parameter p representing an extent to which the polarization plane of all spectral components is rotated, the polarized electromagnetic radiation after passing through the rotator passes through an output polarizer and impinges upon a detector which measures an intensity of at least a single point of the polarized electromagnetic radiation for plural values of the parameter p which produces a set of intensity values comprising a mathematical function of p and wavelength from which at least spectral information is mathematically extracted; and wherein rotation of the polarization plane of all spectral components is not the same for any ray across an extent of the polarized electromagnetic radiation incident on a surface of the rotator.