Patent ID: 7196792

Claim:
A polarimetric system for analyzing a sample comprising: an excitation section emitting a light beam, said excitation section comprising a polarization state generator containing a polarizer polarizing an incident light beam linearly along a direction of polarization; an analysis section comprising a polarization state detector containing an analyzer analysing a light beam linearly along a direction of analysis; detection means; and a processing unit, wherein, said polarization state generator comprises first and second liquid crystal elements, the second liquid crystal element being nearer an exit of the polarization state generator than the first liquid crystal element, each polarization state generator liquid crystal element having i) an extraordinary axis defining an orientation angle with respect to the direction of polarization, and ii) an ordinary axis defining a retardation with respect to the extraordinary axis, said polarization state detector comprises first and second liquid crystal elements, the second liquid crystal element being nearer an entry of the polarization state detector than the first crystal element, each polarization state detector liquid crystal element i) an extraordinary axis defining an orientation angle with respect to the direction of polarization, and ii) an ordinary axis defining a retardation with respect to the extraordinary axis, the orientation angles of the first and second polarization state generator liquid crystal elements are equal to the orientation angles of the respective first and second polarization state detector liquid crystal elements, and the retardations of the first and second polarization state generator liquid crystal elements are equal to minus the retardations of the respective first and second polarization state detector liquid crystal elements, modulo 2π.