用光纤光栅传感器测量外压力的动态调制方法

为了提高光纤布拉格光栅压力传感器的精度和降低系统成本，提出一种使用光纤双布拉格光栅测定压力的测量方法，即在外界压力作用下，传感光纤布拉格光栅反射波长的飘移被转变成在交变力策动下发生弯曲的等强度悬臂梁调制的扫描光栅的反射光脉冲间隔的变化。实验结果表明：光纤布拉格光栅反射波长漂移的测量范围为0～3nm，波长测量的不确定度为1pm；压力传感器的量程为0～6MPa时，压力的测量不确定度为0.005MPa。

Dynamic demodulation method for external pressure measurement with fiber grating sensor

A demodulation method for measuring the pressure with the fiber Bragg dual-grating is put forward to improve the precision of fiber Bragg grating (FBG) pressure sensors and reduce the cost of the measurement systems.Under the action of external pressure,the reflected wavelength drift of sensing FBG is transformed into time interval variation of light pulse reflected by the grating,which is modulated by means of driving the equally intense cantilever beam into up and down bending periodically.The experimental result shows that the detection range for the reflected wavelength drift of FBG is 0～3 nm,the uncertainty of wavelength detection is 1 pm,and the uncertainty of the pressure measurement is 0.005 MPa when the measurement range of the pressure sensor is 0～6 MPa.