方向可辨的高灵敏度双光纤光栅弯曲传感

he degree of bending in the bridge, construction and other fields need to be strictly detected. Dual grating bending sensing device has simple structure, using the copper to support grating and as the carrier to translate the bending, controlling the bending degree by the displacement and detecting the change of cengter bragg wavelength by optical vector analyzer (OVA). The bending sensing properties of optical fiber bragg grating (FBG) and polymer optical fiber bragg grating (POFBG) were studied and analyzed from experiment and simulation. The results show that POFBG has the higher bending sensitivity and larger bending range. The thicker of the copper sheet, the higher sensitivty of the sensors. Furthermore, we put two kinds of fiber gratings adhered to copper two sides respectively to test the dual optical fiber grating bending sensing property. In the bending range of ±4.2m^(-1), the dual optical fiber grating bending sensor realizes the sensitivity of 0.92nm/m^(-1), which the bending direction can be judged by the wavelength discrimination between the FBG and POFBG.