Fibre-optic sensing applications of a pair of long-period fibre gratings

Abstract

We will discuss fibre-optic sensing applications with high resolution and sensitivity that are based on a pair of long-period fibre gratings (LPFGs) characterized by a fine interference fringe pattern and a narrow bandwidth. The dependence of the shift in resonance wavelength and change of peak depth of a pair of LPFGs pair on changes in the external environment such as the bending curvature, transverse load and surrounding index are investigated experimentally. The temperature sensitivity of the LPFGs was suppressed to 0.002 nm ◦ C −1 in order to reduce the effect of temperature on the performance of the sensor.