高灵敏度的光纤光栅压强传感器

A High -Sensitivity in-Fiber Bragg Grating Pressure Sensor

基于光纤布拉格光栅传感模型 ,提出了一种等强度梁与波纹管相结合的高灵敏度的光纤布拉格光栅压强传感器 ,推导了光纤布拉格光栅反射波中心波长相对偏移量与压强之间的解析关系式 ,从理论和实验上给出了压强灵敏度系数。该传感器的理论和实验压强灵敏度系数分别是 1.4 76× 10 -2 MPa-1、1.35× 10 -2 MPa-1,是裸光纤光栅的 74 5 5倍和 6 80 8倍 ,理论值与实验值吻合得很好。同时指出通过调节等强度梁和波纹管的参量 ,可以将该传感器的压强灵敏度系数做得很高 ,直至破坏了光纤布拉格光栅。

Based on in-fiber Bragg grating sensing model, a high -sensitivity in-fiber Bragg grating pressure sensor was proposed by using uniform strength beam and bellow. The analytical formulae between pressure and relative shift of Bragg wavelength of in-fiber Bragg grating were derived. The pressure sensitivity coefficients were also obtained by analytical formulae and experiment respectively. The theoretical and experimental pressure sensitivity coefficients could reach 1.476×10 -2 MPa -1 and 1.35×10 -2 MPa -1, which were 7455 and 6808 times of that of the bare -fiber grating respectively. The experimental result fits the theoretical one well. At the same time, it was pointed out that the pressure sensitivity coefficients of this kind of sensor could be very large by regulating the parameters of strength beam and bellow till the in-fiber Bragg gratings were damaged.