一种可重构型相移光纤光栅传感系统

A reconfigurable phase-shifted fiber grating sensor system

为了实现对相移型光纤光栅传感器回波光谱中相移幅度、位置的精确控制,提出了一种利用机械微应变控制相移光纤光栅传感器的方法。该方法采用千分尺螺杆、应变梁、相移型光纤光栅、解调仪等组成。通过千分尺螺杆完成微应变控制,由梁将应变传递给PSFBG,从而使回波光谱变化,最终,构建光谱偏移量与微位移Δy的函数模型。通过应力加载实验,结果显示拉伸与压缩可以使PSFBG产生正相移和负相移,相移拟合曲线是线性的,综合拟合斜率为0.9914。该系统可通过梁弯曲微应变实现对相移的连续调谐,相移的大小可通过改变负载位移实现线性控制。该方法简单、精度高、控制范围大且无源,具有一定的应用价值。

In order to achieve precise control of phase shift amplitude and position in the echo spectrum of phase-shifted fiber Bragg grating(PSFBG) sensor,the method to control PSFBG sensor using mechanical micro-strain was proposed.There were micrometer screws,strain beams,phase shifting fiber gratings,demodulators,etc.in this method.The micro-strain control was performed by a micrometer screw,and the strain was transmitted to the PSFBG by the beam,thereby changing the echo spectrum.Finally,a functional model of spectrum offset and micro-displacement Δy was constructed.Experimental results show that stretching and compression can cause positive phase shift and negative phase shift of PSFBG,the phase shift fit curve is linear,and its comprehensive fit slope is 0.9914.The system can achieve continuous tuning of the phase shift by bending the micro-strain of the beam.The magnitude of the phase shift can be linearly controlled by changing the load displacement.The method is simple,high precision,large control range and passive.It has certain application value.