非均匀磁光光栅干涉结构的磁场灵敏性

Magnetic-field sensitivity of the interference structures based on nonuniform magneto-optic gratings

根据分段均匀模型分析了非均匀磁光光纤光栅(MFBG)与相应非磁性光栅的等效性,从而可直接利用OptiSystem仿真软件研究非均匀MFBG的光谱特性。在此基础上,深入研究了基于非均匀MFBG的Michelson干涉结构,分析了相位补偿法用于磁场测量的工作原理。仿真结果表明,线性啁啾MFBG的磁场灵敏性高于均匀和切趾MFBG的情形;优化MFBG的线性啁啾系数,可有效提高磁场灵敏度。所给出的OptiSystem仿真模型不但有助于Michelson干涉结构的设计,而且可以用于分析Mach-Zehnder干涉磁场的灵敏性。

According to the piecewise-uniform grating model, the equivalence of nonuniform magneto- optic fiber Bragg gratings（MFBGs） and the corresponding non-magnetic gratings was analyzed which was used to investigate the spectral properties of nonuniform MFBGs by means of the OptiSystem simulation software. On this basis, the Michelson interference structure using the nonuniform MFBGs was studied in detail for magnetic field measurement by the phase compensation method. The simulation results show that the linearly chirped MFBGs possess the higher magnetic-field sensitivity than the uniform or apodized MFBGs, and the magnetic sensitivity can be effectively improved by optimizing the linear chirp parameter. The presented OptiSystem simulation model is not only helpful for the design of the Michelson interferometers, but also applied to the Mach-Zehnder interference system.