Static tensile strain is applied to polymer optical fibre Bragg gratings for the strain sensing characterization. Experimental results indicate that the strain coefficient of polymer fibre Bragg gratings is larger than that of silica fibre Bragg gratings. It is also demonstrated the large strain sensing range with good reproducibility, reversibility and repeatability is achieved. As a result, the study shows the great potential of polymer fibre Bragg gratings in the fibre strain sensing applications.
We develop a simple strain sensor using polymer optical fibre Bragg grating and long period fibre grating. The sensor head is formed by a polymer optical fiber Bragg grating. A long period fibre grating is used for strain related wavelength shift demodulation. This particular combination of two quite different gratings could offer very large dynamic, up to tens of thousands micro-strains, for strain sensing. The preliminary experimental results have demonstrated that this sensing scheme provides good linearity, high resolution and large dynamic range.