Absolute and simultaneous strain and temperature measurements by a coherent optical fiber sensor

A novel non-incremental interferometric fiber optic measurement method for simultaneous detection of temperature and strain is reported. The fiber cross sensitivity to strain and temperature is removed by a simultaneous reading of the optical path length and of the dispersion characteristic of the sensing fiber. The reported experimental trials confirm the effectiveness of the method to recover the static strain and temperature values with 1°C • m and 10?? • m resolution, respectively.