A Strain Sensor based on a combination of a polymer fibre Bragg grating and a silica long period fibre grating

We develop a simple strain sensor based on the combination of a polymer optical fibre Bragg grating as the sensor head and a long period fibre grating as the wavelength shift interrogator. This particular combination of two quite different gratings offers very large dynamic range, up tp tens of thousands micro-strains, for strain sensing, because of its intrinsic special charateristics of polymer fiber Bragg grating. The preliminary experimental results have demonstrated that this sensing scheme provides excellent linearity, high resolution and wide measurement range with simple system configuration and inexpensive cost