Polarimetric parameter measurement systems and methods for measuring a

Abstract

A systems for measuring the value of a plurality of parameters includes an optical fiber having a core that conducts coherent light along two orthogonal polarization axes at different velocities, e.g., an elliptical core, a light source for launching linearly polarized coherent light into such fiber to propagate therein as multimodes, a light splitter to divide the light that emerges from the optical fiber into a plurality of light portions, a mode stripper to remove the second order mode of light from the first light portion, a first polarizer to polarize such first light portion after it exits the mode stripper, a first photodetector to convert the polarized first light portion into a first electric signal, second polarizer to polarize a second light portion, a second photodetector to convert the polarized second light portion into a second electric signal, a signal processor to convert the first and second electric signals into a pair of analog voltages, and meters or the like to display such voltages as parameter values, e.g., strain and temperature. The systems may include a third polarizer and third photodetector to process a third light portion for a third parameter measurement, e.g., pressure. Parameter value measurement methods using the new systems are disclosed.