Patent ID: 8199328
Filing Date: 2012-06-12
Classification: G01B,G01J,G01N

Abstract:
1. A method for measuring the optical rotation of a polarized light beam by an optically active substance, using a polarimeter based on a modified Fizeau interferometer, comprising the steps of: a) generating by a laser a first coherent light beam of a first frequency; b) linearly polarizing said first light beam by passing it through a polarizer so that its electric field vector becomes parallel to the main plane of the polarimeter, defined by the polarizer's transmission axis and the beam's direction; c) directing said first linearly polarized light beam through a modified Fizeau interferometer, whereby: d) splitting said fourth light beam into fifth and sixth linearly polarized orthogonal light beams; e) directing said fifth linearly polarized light beam, whose electric field vector is perpendicular to the polarimeter's main plane, to a reference photodetector and generating a reference signal; f) directing said sixth linearly polarized light beam, whose electric field vector is parallel to the polarimeter's main plane, to a measurement photodetector and generating a coherently detected measurement signal; and g) storing and processing said reference and measurement signals and generating comparison signals using said reference and measurement signals, said comparison signals indicating the polarization rotation angle imparted to said linearly polarized measurement light beam by said optically active substance.