Two-dimensional fibre grating packaging design for simultaneous strain and temperature measurement

This paper demonstrates a novel two-dimensional sensor packaging design to facilitate the use of fibre grating-based sensors for simultaneous strain and temperature measurement. The width and height of a sensor package were optimized to induce dissimilar responses from two co-located fibre gratings within the sensor head. Through an appropriate calibration of both the strain and temperature coefficients of the individual fibre gratings used, both strain and temperature can be accurately determined and their individual components separated by measuring the shift in their respective Bragg wavelengths. This approach can not only ensure the robustness of the sensor head, but also offer the necessary level of control over the differences between the coefficients, which allows for maximizing the accuracy of the strain and temperature values determined from the sensor itself.