高非线性光纤中四波混频的磁控机理研究

将磁光效应和光纤非线性效应作为微扰,采用导波光耦合理论分析了高非线性光纤中导波光发生磁光四波混频的机理;实验测试了磁场对四波混频偏振依赖性的影响,理论分析与实验结果符合.研究表明,当输入的探测光和抽运光为相互正交的线偏振光时,四波混频的磁控效果最为明显,输出的闲频光功率随磁光耦合系数振荡变化,施加适当的外加磁场可使四波混频效率得到进一步提高.选择适当费尔德常数的光纤材料,利用磁光效应对四波混频偏振依赖性的影响,可实现不同范围的磁场测量.

Research on magnetic control mechanism of four-wave mixing in highly nonlinear fiber

According to the coupled-mode theory for guided optical waves, the mechanism of magneto-optical four-wave mixing (MO-FWM) existing in a fiber with magneto-optic effect and nonlinear effect both serving as perturbation is analyzed. The influence of applied magnetic field on the polarization dependency of FWM is measured, and the experimental results are in agreement with the theoretical analyses. It is shown that the magnetic control function of FWM can be identified easily for the incident orthogonal states of polarization. The FWM efficiency is dependent on the MO coupling coefficient in the oscillation form and can be further improved under an appropriate bias magnetic field. The MO-FWM effect can also be applied to magnetic field sensing, and the operating range is determined by the Verdet constant of highly nonlinear fiber.