Patent ID: 7259862
Filing Date: 2007-08-21
Classification: G01B,G01D,G01J,G01K

Abstract:
1. A tandem interferometer optical sensor system, based on low-coherence interferometry, for measuring a physical quantity, the system comprising: a light system generating a light intensity characterized by a coherence length; a sensing interferometer, having a sensor path length difference larger than said coherence length, for receiving the light intensity and generating a sensor light signal as a function of said sensor path length difference, wherein said sensor path length difference is modifiable by a variation of the physical quantity; and a polarization readout interferometer, having a readout path length difference and based on two-beam interferometer configuration, receiving the sensor light signal and generating, at an output location and as a function of said readout path length difference, a readout light signal, said polarization readout interferometer comprising an input polarizer for decomposing the sensor light signal into two linear orthogonal polarization components, a single birefringent wedge in which are propagating at different speeds said polarization components, an output polarizer for recombining after propagation in the wedge the polarization components, and a focusing optic arrangement for relaying the received sensor light signal through the input polarizer, the birefringent wedge and the output polarizer and towards said output location, to thereby provide the readout light signal as a function of the readout path length difference.