【摘要】 针对基于磁流体的光纤磁场传感系统依赖复杂的光谱解析且易受光源功率波动影响的问题，提出了一种基于光时域反射计(OTDR)的磁场传感系统，用包裹磁流体的锥形光纤作为磁场传感单元实现磁场测量。不同磁场强度下，磁流体磁光效应导致磁场传感单元的光损耗变化，系统衰荡脉冲包络斜率特性改变。将磁场强度与脉冲包络斜率建立联系，实现了磁场测量。实验证明：在30～130 Oe(1 Oe=80 A/m)的测量范围内，传感系统磁场灵敏度为-0.047 1 dB/(km·Oe),且衰荡脉冲包络斜率与磁场强度之间呈现出良好的线性关系。研究表明：该方案提供了一种测量磁场的新方法，且解决了光功率波动影响稳定性的问题。更多还原

【Abstract】 Aiming at the problem that the optic fiber magnetic field sensing systems based on magnetic fluid rely on complex spectral analysis and are susceptible to fluctuations in light source power, a magnetic field sensing system based on optical time domain reflectometer(OTDR) was proposed.To achieve magnetic field measurement, a tapered optical fiber wrapped in magnetic fluid was utilized as the magnetic field sensing unit.Under different magnetic field intensities, the magneto-optic effect of the magnetic fluid caused changes in the optical loss of the magnetic field sensing unit.The ring-down pulse envelope slope characteristics of the system was altered.Relationship between magnetic field intensity and pulse envelope slope was constructed to achieve magnetic field measurement.Experimental results demonstrate that within the measurement range of 30～130 Oe, the magnetic field sensitivity of the sensing system is-0.047 1 dB/(km·Oe).Moreover, there is a good linear relationship between the slope of the ring-down pulse envelope and the magnetic field intensity.Research shows that this scheme provides a new method for measuring magnetic fields and solves the problem of stability affected by optical power fluctuation.更多还原