Patent ID: 6404503
Filing Date: 2002-06-11
Classification: G01D,G01R

Abstract:
Apparatus for the measurement of physical quantities, of the type using a transducer to convert the physical variations of a physical quantity in variations of the plane or state of polarization of a polarized light beam, characterized in that:the transducer (38; 48A; 58A; 68; 78) is inserted in an optical circuit (I) being provided with polarizing beam-splitter means (33A; 43A; 53A; 63A; 73A;) for splitting the light beam into components having a different state of polarization, and to launch them along a first optical path (A) and a second optical path (B), being different from each other, which meet in further polarizing beam-splitter means (33B; 43B; 53B; 63B; 73B), arranged at the output of the optical circuit (I), which recombine said components; at the output of the optical circuit (I) a reflector element (6; 16; 36; 76;) is provided which produces a change of the plane of polarization of the light beam and reflects the light beam back in the optical circuit (I).