| Over the past two decades a wide variety of fiber optic sensors have been developed. A Brillouin scattering based fiber optic sensing system has been developed at UNB. Systems of this type are capable of measuring continuous distributions of either strain or temperature along the entire length of the optical fiber through measurement of the Brillouin frequency shift. However, ambiguity in the measurement of strain and temperature arises due to the cross-sensitivity of the Brillouin frequency on these parameters.; Recent advances in the automation of the sensing system has allowed for the entire Brillouin spectrum to be measured. In this thesis, the Brillouin loss spectrum will be characterized in terms of its center frequency, peak power, linewidth and shape. These parameters will be considered as a function of the input pump and probe laser powers, the pump pulse duration (width), strain and temperature. Characterization of the Brillouin spectrum led to the development of an innovative technique to measure the strain and temperature simultaneously using the strain and temperature dependence of the peak power in conjunction with the Brillouin frequency. |
