METHOD OF AND DEVICE FOR REAL TIME MEASUREMENT OF THE STATE OF POLARIZATION OF A QUASI-MONOCHROMATIC LIGHT BEAM

摘要

An interference technique is used to measure the state of polarization of a quasi-monochromatic light beam. Two quasi-monochromatic radiations with slightly different optical frequencies are generated. One radiation is converted into a 45.degree. linearly polarized radiation, whilst the other presents the polarization state imposed by a body under test. In each radiation, horizontal and vertical polarization components are separated, and the horizontal and vertical components are then respectively recombined into two different beams each comprising radiations at both frequencies, polarized in the same plane. Beats between the two components in each beam are generated and used to generate two electrical signals in the radio frequency range, from which information is extracted as to the relative phase and the amplitude of the two components of that radiation whose polarization is imposed by the body under test.