Fiber optic sensor having a multicore optical fiber and an associated sensing method

A fiber optic sensor and associated sensing method includes a multicore optical fiber having first and second optical cores adapted to transmit optical signals having first and second predetermined wavelengths, respectively, in a single spatial mode. The first and second optical cores each include a respective Bragg grating adapted to reflect optical signals having the first and second predetermined wavelengths, respectively. Based upon the differences between the respective wavelengths of the optical signals reflected by the respective Bragg gratings and the first and second predetermined wavelengths, a predetermined physical phenomena to which the workpiece is subjected can be determined. For example, the fiber optic sensor can include strain determining means for determining the strain imparted to the workpiece. Alternatively, the fiber optic sensor can include temperature determining means for determining the temperature to which the workpiece is subjected. Further, the fiber optic sensor can include both strain determining means and temperature determining means for simultaneously determining the strain and temperature to which a workpiece is subjected. The fiber optic sensor also includes calibration means for measuring the predetermined physical phenomena, independent of variations in other physical phenomena.