Extending fiber sensors beyond temperature and strain
The Center for Photonics Technology (CPT) is developing sensor technology for long-span, fully-distributed measurement of pressure and transverse stress – two parameters that cannot be measured by any available conventional technology, according to CPT director Anbo Wang. The technology will extend fiber-optic distributed sensor technology beyond its traditional functions for temperature and longitudinal strain only.
The breakthrough technology is expected to find a wide range of applications in oil and gas production and delivery, real-time highway assessment, earthquake prediction, volcano monitoring, and structural health evaluations.
The research team is combining specially designed optical fibers with a novel technology recently developed at Virginia Tech: grating-assisted polarization-optical time-domain reflectometry (GA-POTDR). GA-POTDR interrogates the fiber in a fully distributed manner with high resolution and high accuracy.
“The technology provides a large degree of freedom in system design, which can be exploited to achieve previously unattainable performance,” Wang said. “By controlling the fiber reflections, we will achieve a uniform signal-to-noise ratio along the fiber regardless of the power consumptions from previous sensor sections. By optimizing the fiber design, we could greatly enhance the measurement sensitivity while maintaining its low temperature cross-sensitivity.”
The project is funded by the National Science Foundation. For more information, visit www.photonics.ece.vt.edu.