Low-Cost Technique for Measuring Distributed Strain and Temperature in Long Optical Fibers

We propose a novel Fourier transform based fiber optic sensor for distributed strain and temperature measurement. The proposed sensing system consists of a wavelength tunable light source, a single mode polarization preserving fiber, a photodetector, and a simple Fourier transform chip. The whole system works like a Fourier transform spectrometer. By scanning wavelength and taking the Fourier transform of the recorded data, the information about the location of the pertubation can be retrieved. To measure the strain and temperature simultaneously, we shall first use the birefringence dispersion. The major advantages of the proposed distributed fiber sensor are the high axial resolution (<1cm) and the simultaneous measurement of strain and temperature (which cannot be done using other existing techniques). The proposed research will result in a practical distributed fiber sensor for both military and commercial applications.