光纤F P腔干涉纳米级位移高分辨率测量

激光抗干扰性好、复用能力强,光纤F P腔干涉仪结构简单、灵敏度高,适于纳米级位移测量。为了进一步提高分辨率,扩展测量范围,本文对光纤F P腔干涉信号的相位和功率进行分析。首先给出了二倍次方功率和分辨率的关系,找出了提高分辨率的途径。然后给出了二倍次方功率和干涉条纹变化的关系,确定了测量条件。最后根据光纤波在F P腔内干涉形成的滞后相位,通过多次希尔伯特变换,实现了待测物体位移重构。数值模拟和实验证明了该方法能够实现高分辨率纳米级位移测量,误差小。

Fiber optic F P cavity interferometric nanoscale displacement high resolution measurement

Good laser anti interference and multiplexing capability,simple structure and high sensitivity of fiber optic F P cavity interferometer,suitable for nano scale displacement measurement.In order to further improve the resolution and extend the measurement range,the phase and power of fiber optic F P cavity interferometric signals are analyzed in this paper.Firstly,the relationship between the power of the quadratic power and the resolution is given,and ways to improve the resolution are identified.Then the relationship between the power of the quadratic power and the variation of the interference fringe is given,and the measurement conditions are determined.Moreover,based on the hysteresis phase formed by the interference of the fiber optic wave in the F P cavity,a multiple Hilbert transform is used to reconstruct the displacement of the object to be measured.Finally,the displacement of the object to be measured is reconstructed by multiple Hilbert transformations based on the hysteresis phase formed by the interference of the fiber optic wave in the F P cavity.Numerical simulations and experimental results demonstrate that the method can achieve high resolution nanoscale displacement measurements with small errors.