Three-axis strain and temperature fiber optic grating sensor
Proc. SPIE 2718, Smart Structures and Materials 1996: Smart Sensing, Processing, and Instrumentation, 104 (May 30, 1996); doi:10.1117/12.240852

For many applications it would be highly desirable to be able to measure all three axes of strain and temperature internal to composite materials. Conventional electrical strain gauges are undesirable to embed into composite materials because of their size, conductive nature, susceptibility to electromagnetic interference, incompatibility with the host material and temperature limitations. All of the tests done to date with single element fiber sensors have been limited to the measurement of strain in the in plane dimension. This paper describes an innovative fiber sensor based on dual overlaid fiber gratings on short lengths of birefringent polarization preserving fiber that allows three axes of strain and temperature to be measured at a single point.