利用双臂Mach-Zehnder光纤干涉仪测量磁场强度的结构是将其一臂涂覆某种磁致伸缩材料作为敏感臂,另一臂作为参考臂.假如把它们同置于待测磁场中,则通过两者的光束将出现光程差或相移,可据此测定磁场强度.实际上,铁磁材料都存在磁滞性和剩磁性,以致后续的测量值不确定.为解决这个问题,作者们将敏感臂置在V_0和V_s电源所激励的交变磁场中,见图1.V_0所激励的正弦交变磁场幅值较小,频率选用远高于常规干扰信号的基频,作 The structure of a magnetic field measured by a two-arm Mach-Zehnder fiber-optic interferometer is that one arm is coated with a magnetostrictive material as a sensitive arm and the other arm is used as a reference arm, and if they are placed in the magnetic field under test The optical path difference or phase shift between the two beams will be measured, and the intensity of the magnetic field can be measured accordingly. In fact, the ferromagnetic material has hysteresis and residual magnetism, so that the subsequent measurements are indefinite. We will be placed in the sensitive arm V_0 and V_s power excitation of the alternating magnetic field, shown in Figure 1.V_0 excited sinusoidal alternating magnetic field amplitude is smaller, the frequency selection is much higher than the conventional interference signal of the fundamental frequency for